Starting A levels, can someone tell me how do I stay motivated about grades??

I just started AS and I'm feeling very unhopeful right now. My subjects are compsci, English and math, and there's been many paper leaks of math recently. Not to mention I've seen pretty much everyone get Cs, Ds and Ungraded for their result, and these people out here were doing the MOST.

I'm not an insanely smart academic person but I'm willing to put in the effort to get As, but how exactly do I get them is my question?? If the smartest ppl are somehow getting horrible grades they weren't expecting at all, how am I gonna get any good ones?

Does anyone have service on how I can be consistent and get a good grade like A or A*? Pretty much evrryone in my life including teachers seem unhopeful about getting As, so I don't know what's worth the effort.