And the very first thing you'll need to do is to read the "Cycling a Tank" link that's at top of the forum page.
This explains how to do a 'fishless' cycle in order to get the filter and bacteria ready BEFORE you put in any new fish/stocking you going to put in your new tank.
If you do a 'fish IN cycle' that means a lot more work and water changes plus any mistakes made WILL affect your fish and they'll suffer for any mistakes. Hence why fish less cycle is always recommended.
Have you any idea what sort of fish you would like?
By the way, we're pretty much a nosey bunch around here so please post pictures up when you can, we love seeing pictures.
If you ever get stuck or unsure about anything then be sure to ask on this forum, we love to give advice and help when we can.