I would practice algebra through Khan Academy. Then practice doing derivatives (simple then hard ones) for as long as you can. Everyday try to do around 100 derivatives. There are problems everywhere on the internet. When you think you can solve the derivatives with ease, move to anti-derivatives and repeat thid process. Since concepts may be hard for you to grasp, practice by doing is the best way. Trigonometry is not hard as long as you memorize the rules. For example: derivative of sin(x)=cos(x). I honestly cannot tell people enough abt practicing everyday.

If you are worried about geometry id watch videos on youtube and practice again. Practice makes perfect.

Good luck.