You can see the achievements you have if you hit the experience tab toward the top of the forum, just underneath the TFF banner. There's two little boxes on the top right, one listing your awards and one listing your achievements. If you hover your cursor over each icon it'll tell you what the achievement is, more or less.

Then if you hit the achievements tab, it lists all the ones that have been discovered so far. They're more or less in categories. The ones with green checkmarks are what you've earned. I don't think they've been updated fully yet, as I should have the achievement for 10,000 experience points, but the one that I have listed is for 250 points. Just a little off. I'm sure it'll take a bit to work all this sort of stuff out.