At level 20 my equipment was much more average than at the end of the game. There are a couple legendary quality items available earlier than that, but normal equipment at level 20 isn't unusual.
Where are you now, sentinel island or the fjords?
Once you get the battle tower, if you fly around the fjords and check out wyvern nests until you find at least one each of the 3 different zeppelin parts (there are 9 total, 3 of each) you can get access to Aleroth (at the Zeppelin pad on top of the harbour building), where there are a couple merchants with legendary quality items for sale. The merchant in high halls starts carrying legendary equipment, as well, once you get your level high enough (about 30?).
If you are having trouble, or need to replace a particular piece of equipment, you can go around to all the traders each time you level. Save before running your crosshairs over them, and you can check their inventories, and reload if they don't have something you can use.
Generally, though, if you just keep playing you should find upgrades as you go.
What type of character do you want to play? Start focusing on the main stat(s) for the type of build you want to make. I had high strength and low spirit, playing a duel wielding warrior, but the other 3 stats ended up pretty comparable. I also had lots of spare stat points unassigned, so investing 'too much' in a stat you end up not focusing on shouldn't be a problem.
Character OptimizationIf you have to read about someone else's build to think you have a problem though, you may not actually have a problem. Unless of course you were reading up on builds because you started running into difficult areas where nowhere else to try first.
In any case, there are a variety of effective character builds, and you do not need to get every quest and have the perfect stat and skill distribution to be able to complete the game.