I need advice on how to get Astros merch appraised and then where I could possibly sell it.

I don’t do this kind of thing and I’m only asking for advice on what to do next. I’m currently in the Navy right now, but my ship date is set all the way till September 8 mainly because I didn’t score very well on the test. I was able to meet this months rent, however next three months after this, I can meet, but I’ll have to go into my savings to meet that. Right now I’m unemployed and I’m just trying to figure out where I can get this appraised and have it be authenticated and then where I can go sell it. Any advice at all would be much appreciated.