I agree with all of the above especially Lightcycle's advice of working on fundamentals and consistency. For me, YouTube videos have been very helpful to improve little by little e.g. the ones you posted in another thread here.
I started with Racer5 in 2018, blown knee kept me out 2019, green group 2020, green Calabogie / yellow Shannonville 2021. I'm going back to Racer5 for the Continuation Program in May as a refresher. The amount of time you get out on track I feel is great to work on the fundamentals, and the crappy suspension on the 125/250cc bikes makes you work even harder to avoid upsetting the bike - forces you to be smooth.
My thought process generally - study track beforehand, tire pressures, learn track, marshalls position, passing zones, get familiar with markers, racing line, gears, how one corner affects the next, relax, be smooth, be consistent, braking markers, am I getting on throttle too early?, try braking a little later at markers, relax again, notes, reflect on where I could be fast, work on corner exit / smooth on throttle, arm position, body position, once I'm at a decent enough pace - comfortable and consistent, I start thinking about suspension.
I do prefer yellow at Shannonville with Riders Choice despite the mentioned stoppages. I find green sometimes has new riders that are really unpredictable - easy to spot but if you haven't got much power and they do - can be a little scary. I'm completely happy with green at Calabogie with Pro6.