nice to meet you and to join you in the cartographers guild. I have been DMing for a very long time and enjoy world building. Alas, I am not very gifted with either drawing talents nor computer design skills, so every map is a hard job for me. But I am sure, that you will be able to give me good advice on any programs and tools i could use!
Cheers, and good luck,
You've come to the right place! A great way to start is to read the Quickstart Guide to Fantasy Mapping sticky in the Tutorials forum. It lists several different beginning tutorials in different styles and using different programs, any of which will set you on the road to great maps :)
Welcome to the Guild Wickedberry, I second what Gidde said.