Read. This. Forum.

Many of your questions are answered here in the first page or two of posts. After the game there is little to do but explore those areas you missed while playing the campaign. What ship should you get? Whatever ship lets you do that. The amount of money listed is how much more you need for the next level. When you hit level 20, you can get a better ship than the Anubis you likely finished the campaign with. The ship you were promised was the Anubis Heavy Fighter. It's a little misleading because you're able to buy this fighter right after landing on the Osiris and meeting Orillion for the first time. He never "gives" it to you, exactly, but you'll notice it costs very little to buy. If you didn't buy it before finishing the campaign... you missed your chance. It's not sold anywhere but in the single-player campaign either on the Osiris or on the Order base on Toledo.