Pls help

Hello. I’ve been using makeup since about last September on and off. I’m now looking into a makeup ‘prep’ phase where you prep your face so the makeup goes on better. I’ve looked at so many videos and they all give different results. Some ‘swear by this product’ and others say it’s terrible or made them break out. Please. I’m just looking for some good products that will make my makeup better. I use mac foundation and the Dior concealer.