it is gonna be a tough task if you are talking about memorizing characters , however things will be easier ,if you try some tools , for example, Anki
.google it, it will help you a lot . And as for grammar, systematicallly learn it from a text book seems to be a must if you are not in a Chinese speaking country, btw, add me ,if you like, my Skype ID is : windsofchengdu. I can do my best to help you learn Chinese,as the only thing for exchangging, I need you to sharpen my ears,cuz I have a poor listening lol...