I heard something about enemies matching with the player when it comes to leveling up. Like enemies will not become any easier as you level up, they will continue to be hard. So do dragons follow this? If I level up a lot, can I hope to one day be able to defeat dragons easily? Because currently I've only killed 2 ...

sorta...you run into different variations...starts off with basic dragons then you get into blood dragons and some others.

There are different kind of dragons which have different stats. But in a term of stronger vs you or on par with you you mean? In my playthrough I've found the dragons become easier and easier (unless they get lucky and instant kill), but that's maybe because they way I play. Max 2h sword, max heavy armor, max blacksmithing and max enchanting (with max I mean getting the 100 skill point perk, not getting every perk since several of them are not worth getting).

Well you will still see the same garner variety dragon later on in the game, and those will be easy to kill. You will also see much harder dragons as well.

Dragons are ridiculously easy to kill after a while and so they become more of a nuisance than a challenge. It's a shame really =\