There should be no issue with you buying your own goggles, as long as they are actual skydiving goggles. Also, don't get them with tint. Instructors want to be able to see your eyes. As for the helmet, it's likely that the drop zone won't want you to use your own helmet until you are cleared from having to have a radio (the radios are integral to the helmets at my home dz). As for the jump suit, you'll have to run that by your S&TA, but I don't see a safety reason for them to prohibit you from that. Altimeters, same thing: run it by your S&TA. Don't even think about buying your first rig until you're licensed though, and definitely lean on your instructors and the experienced folks to point you in the right direction with any big purchases (altis, rig, suits & clothing, helmet)