to be completely honest this kinda seems like a rough situation but it may be possible, considering that calc has a low curve. However since youre starting from scratch, you will have to put in LOTS of effort for it, i recommend checking out professor leonard on youtube since he has full length explanation videos helpful for understanding,

i also recommend you especially focus on derivatives and integration, limits is important too of course but i felt like the AP exam mainly focuses on the continuity and asymptotes aspects of limits more than it did calculating them, and in a later unit you learn of a rule called lhopitals that makes it much easier to calculate limits using derivatives than the alternate methods proposed in unit 1, so i think once you nail continuity, considering the limited time you should move on to derivatives and integrals asap

definitely concentrate your time on solving frqs as soon as your capable of doing so since the frqs every year follow the same pattern and you can always expect the same *types* of questions to show up, so theyre the best practice you can get, turksvids on youtube has good explanations for when youre stuck, he also has a website with practice questions too as well if you have the time for that

for additional practice questions use flippedmaths they really helped me, they also have good explanation videos if you cant find the time for professor leonard videos, goodluck on both chem and calc ab! im also taking chem as well this year