Hello and welcome,
I would suggest taking the time to thoroughly read the manual start to end and get a good feel for the basics and then move on to any tutorials that I could get my hands on especially ones aimed at your area of interest, fps or strategy for example. Read through all you can and get a good feel for what to do and then start by creating a small, very small, game of your own. Something like a one level shooter or a simple puzzle game. That should get you going and give you a good idea of what is involved.
Once you get your bearings and if you like you could find a team to join up with. You can learn a lot from one another in a team and together you can work on bigger projects and have a better chance of seeing them through to the end.
Hope that gives you a general idea of a direction to embark upon. Good luck. See you around the forums I hope.