im weak

i cant lift a lot and don’t now what to do to gain more strength

Well gaining strength takes time. You need to make sure that you are following a consistent plan that utilizes the rules of proper periodization. All of the MF Trainer programs have been designed this way, so as long as you follow your program under My Workouts you will start seeing results. Consistency is key so get to it. Let me know if you need some guidance.