PC2 isn't a truly realistic sim, like rfactor or iracing. It has intricacies that are not realistic (so much so they are still being tweaked with consumer patches/complaints), so like any game it will take time to learn these and work around them. Once you do, if you're any good, you'll pick it up.
My advice would be to pick a simple low powered car, tune your FFB so you can understand what the FFB forces mean (this will take an hour at least), then learn how different parts of the track affect grip like kerbs, debris, grass, dirt and different grip levels of circuits (another hour or 2), learn tyre temps and pressures (another 2 hours), pick clear warm conditions - ignore the fancy stuff of all the live track options like day/night, wet/dry, cold/hot. This will take you a day of perseverance. Worry about fiddling with setup, serious racing cars and live track later. Find a database of fast lap times for a car:circuit combo and try a free practice session until you can get within a couple of seconds (several hours depending on your ability).
Above all; consider that the SMS team know their physics model to the mathematical level and have designed their game around their own understanding of these. Going outside of the maths (like spearing off the track) will penalise you harsher than any real world experience would have you expect. It will take you weeks to come close to a similar level so perseverance is key.
Do not make the mistake to comparing the physics to other racing games.