I'm really nervous that I have copy's of things on my HD like pictures. How can I make sure I'm not taking up all that space and How can I check on how much memory I'm using out of the 2GB's that I have?
Try something like Disk Inventory X for disk usage ( their are other that do this like WhatSize etc ) to check how much RAM is being used go into disk utilities & take a look at your Activity Monitor also to determine if you need more RAM look at the ratio between your page in & page out's, here's a guide from MacRumors to help you understand this more