Noob about ladder

Hey guys, I played last ladder only few days, I don't know much about D2, I want a good start for once and would like to push for 99.

I will play javazon, what advices would you give to a noob ?

What should I keep in my stash, should I play with other people to rush to hell or chill solo and kill everything I can ?

Any advices would be great, thanks :)