I am using an interface. It is an M-Audio Fasttrack Pro, but it is nothing special. The G3X does have one built-in, but I have things set up so I can use a microphone too through the M-Audio.
I use Elixir 10 gauge strings. They are coated and so last pretty long. I don't like having to change them too often.
Some advice from me is to post some videos. That gives you incentive to work on something until you are happy for others to hear it. There are so many on-line lessons out there that you can keep swapping between different things, but being able to do one thing well is important. Then you can start on something else.