The first thing I would do, before anything else, is educate yourself on the specs for your system. You need to be familiar with them in detail before you can think about upgrading anything yourself IMO.

But if you have not done this before, there is a risk to doing it yourself. It might be a lot safer for you to have a professional do it. When I first started upgrading my hardware years ago, I fried several motherboards because I did not take proper static precautions. It takes very little static to do damage...so small you would not even feel it.