The importance of Track Knowledge is often either ignored or gets somewhat of a back-seat when new/novice drivers attempt to become fast or stable on a track.
More often then not novice drivers will start to focus on setting up their car, tweaking the settings, fine-tuning it to their preferences or assumptions of what should or could be right way to go. Often because simple track-time is not giving them what they want fast enough or compared to others.
This is all good when a driver knows the sim/car/mod inside out and routinely go's through a setup or simply loads a base setup and start working the track.
But when lacking in-depth or even basic knowledge on setting up a car, it is recommended to ignore the better part of setups and just go out on the track and do as many laps as you can.
Doing a reasonable amount of practise laps will make you faster in a much shorter timespan as opposed to trying to figure the same thing out in the garage first.
As a rule of thumb for novice drivers: spend more time on-track, less in the garage.
Even for advanced drivers and aliens this is often the case, but for them its usually a concious choice as they realise that setups only get you so far. Its what happens on the track that really matters and determines what needs to be done.
More often then not an advanced driver will just load a setup, either a 'latest' one or one that matches the current track characteristics and go out for hot lapping.
Knowing the track
is absolutely essential in becoming a fast driver. Its not just knowing when to turn lef or right, its the in-depth knowledge of bumps, curb-hights, angles, tarmac grip, apexes and whatnot. These little titbits of information will generally tell a driver allot more on how to setup a car and assist them in making the right or more logical choices.
With decent track knowledge you will find that it is much easier to go back into the garage. Now your setup choices are more educated as you will have figured out on-track what you need or want. Experimenting becomes much more of a tweaking game and long practise runs will now be mixed up with short burst of testing what your latest tweak brings you based on what you experienced on-track.
whatever sim/car/mod you are currently using. A base setup
to just get you started is most helpful. For every driver this means something else but its usually either a 'general' setup to be used on the majority of tracks or the 'latest' setup (which in theory is usually an evolution of previous setups and should be your best one available since it was the last one you used)
When using a base setup all you need now is to do a few laps, change gears, maybe change wings a bit and start hot lapping until you can make something of it.
Ignore the dark patches on-track (braking zones/racing lines), start experimenting with your lines. each car/mod requires a different approach, lines change accordingly. Getting stuck in rule-book-lines or tarmac-lines might be counter productive. Also this way you might be able to discover lines/apexes that suit your driving style, setup or car much better.
Follow other drivers on track or follow them from the garage. try to see what they are doing, compare it to what you do.
The amount of laps in practise in order to get to know the track differs from driver to driver so there is no way in telling how much you should do. There are however signs you should watch out for telling you you have reached a certain comfort zone. For example if you get comfortable with the track, are no longer intimidated by the track, when you start going for tenths of seconds instead of seconds, when you feel the car should be better setup wise because it simply wont give you the correct speeds/apexes. These are all signs it is time to get back into the garage and start fine tuning.
If you are still struggling, going off track, messing up braking zone's etc, you still need to do more practice laps.
Don't fall into the tweaking-trap where you randomly start changing settings hoping it will work, this will only lenghten the time before you reach that comfort-zone.
Don't be intimidated by other drivers, especially the really fast ones or those with loads of experience. They usually need much less time then you to become comfortable with the track or car and will start to put in fast laps very quickly. If you focus on their lap times, driving styles, how they attack the track then you might find pressuring yourself and will start to overdrive or simply forget that you needed to cover the basics first.
But when possible ask for their setups! Their setups could well be unusable for you but its always nice and helpful to see what they are actually doing with their car. even the most basic tweaks could help you progress.
If possible in your sim, save your setup changes often and as single setups. sometimes changes don't work well or you forget what you did and overwritten the original file. Just rename the setup from 1 to 2 etc. and you will be able to go back to what you originally was doing or anything in between. Also give your setup the name of a track. a simple Monza_1 will help you in the future as it will be much easier to decide what setup to pick for a new track.
It also an very good idea to test the pitting procedure, driving some laps then requesting a pit stop, and get into, to the pit stop place and out the pit lane as fast and safe as possible. Same goes for a drive through of the pits. This could be crucial in a race and will safe time.
Another thing to explorer on a track is the starting area, testing several starts from different positions helps for the race start. Some grids are in a turn, some go up or downhill, you know these things when you test them and don't get surprised. Just drive an out lap (as pace lap), line up on the grid and try some practice starts.
Track knowledge should also included the starting lights and pit lights. Where are they located? When does the pit light turn green, if you have to start from the pits? In some sims it helps also to know where marshal flags are shown.
Some benefits can be taken from driving a reasonable fast lap on the left and one on the right side of the track, this will help to have more knowledge in racing situations with other cars. Where can i brake late on the inside line, or where can i give easy and safe room to a car lapping myself.
This all is easily explored in test sessions, without the added tension of other people or an race start. rfactor allows one to test starts and race sessions with AI as dummies, its good to try those things!
It helps to know what will happen and focus on the main thing at hand, racing.