[Routine Help] From no skincare to skincare

Hello all, I'm 17 and have recently started caring about my appearance. My skin has never been the best but I am trying to change that, considering I have no money or job I can't go out and buy products. However I've been regularly using simple face wash and a normal face moisturiser after. Luckily my older sister has skincare I can leach off and I don't know what they do but they look fancy, please tell me what to do with them.

The products: Simple face wash, Simple face scrub, Manyo cleansing oil, Manyo Bifidia ampoule mist, La Roche Posay effaclair purifying gel, St Ives blemish control, face moisturiser(idk what one it is sorry), La Roche posah spf 50 sunscreen