Need help for getting good at playing moto gp 20.

hello fellow gamers/ sim racers. I acquired Moto gp 20 a couple of months back when it was on sale in steam and have just gotten around to playing it .. I did try it when I brought it but I didn't have a good controller back then so I stopped after 30 mins and now I came back again.. however I am really really bad at it .. I turned on all the assists and I was able to complete a time trial in quickmode on the Netherlands track..and I was around 400 or 700th place in the leader board.. with all assists too .. and when I started to manual shift and brake i got way worse.. I can't keep the bike to turn properly and I have guided setup with the engineers telling it understeers and still I couldn't turn in properly and Ig it's because of my fault and I don't brake or accerlate properly.. do you guys have any guides or tutorials that you would recommend.. the game doesn't have any... for context I haven't seen any moto gp races in real life .. have seen a few things about racing lines and such in YouTube .. and I haven't played many racing games too .. I have played Forza horizon 4 .. I was bad at that too but I got 70 hours in it .. I used to play need for speed most wanted 2005 when I was a kid.. recently before I bought MotoGP I completed road redemption..and even got almost all the achievements..that's what got me interested to play a proper bike racing game but it's too hard to control the bike properly ... I can understand that I have to touch the apex of the corner and only accerlate out when I am completely off the apex .. but still I can't execute my thoughts into actions properly... i either brake too early or too much and I get very slow lap times or engine brake by going down to gear 1 and picking back up but the other riders are fast