I recently started playing and really enjoying it so far. I want to get myself a new mount but I am not sure which one, and would like some advice.

I play as a Guardian Fighter. Im not sure what kind of build I will be, but I heard they are considered the "tank" class. If thats the case, should I get the one that gives defense?

Any advice would help. Thank you!

I can't really tell you which mount to buy, but what I can tell you is that if you are considering buying a mount, then buy one from the zen store (purple if you can). These mounts are account wide, which means every character on the account can claim the mount as well. so you pay once for unlimited mounts (they will be bound obviously). But ity is better than buying a purple from the AH as those are single ones, and no other of your characters can get those.

I did not know that thanks for the info

You will need a legendary mount to get the % from your character also, get a mount bonus that will help you build.