I’m bad at geometry and it’s application. Keeping in mind that geometrical application is what optics consists of. How should I practice and improve on my problem solving reasoning power?

@ prakriti 
what u need to understand is that optics consists of simple application of geometry , and for that just u need some besic concept to be cleared  . 
so, start optics chapter with h c verma , and then proceeedcon with ncert , after hcv completed , u can check out with the problem solving part . 

u need geometry only to understand the derivatiuon . 
so,betterto start with h cv ,nd before starting make sure u start with MATHEMATICAL TOOLS as that is the main thing and u need that before studying physics at all . 
ALL THE BEST ..

all u need is to learn basics . if your basics are not clear no one can help.

i  m also a student . i can understand ur problem.

i suggest u to start with ease.

so use s.l.arora or modern abc then take the question from hcv .

it is better to do those things first which is hard for u.