Need A Little Help With A Character Build

So I'm new to RPGs in general and I'm jumping into an already in progress campaign with a group of people I found online. I met with two of them the other day and we were going over game stuff and then we went to build my character.

I chose a Human Colonist with the Politico specialization. The GM was walking me through the process but we weren't able to finish up by the time we all had to go. I was going to do the rest on my own but noticed a few things and now I'm confused.

In the breakdown of both Colonist and Politico it says you get one rank in certain career skills without spending any XP...looking at my sheet that I had I didn't do any of that, I was actually spending my starting XP.

I remember investing some starting XP into raising my Characteristics, can you do that in addition to the skills or is that instead of and why I don't remember taking class skills.

Finally, since I'm joining in the middle of the campaign the GM gave me 165 extra XP to spend after initial creation, but since I can't figure out if we made it right to begin with I'm pretty lost.

Any help appreciated.