There are a number of different reasons why one might want to study martial arts. Whatever your reason, one of the main reasons is to learn how to defend yourself against a would-be attacker who will attack you. The best thing that you can do to prepare yourself for such an attack is to know what you need to do. If you know that you need to train regularly, then you need to set up a regular training schedule. If you know that you need to get good at punching, then you need to train your muscles to exert more force.
Once you have made that decision that you need to train, and you have set up the sessions that you know you need to attend, you need to be sure of two things:
1) That the sessions are realistic - in the vast majority of cases the attacker does not give a flying snot what you think about doing, and in most cases what you think about doing is not w