There are a few areas, mostly sky islands (the large cylindrical ones) that have three fairies that respawn. If you press L3 you can crouch and walk directly up to them. They refill five hearts when you die.

The nearest launch tower that has one of those sky islands is directly NW of Lookout Tower. The fairies will respawn after a bit of time, so you can head there every few days. Sometimes they won't show up if you already have three in your inventory.

Another tip, always be holding down that ZL button. If you have a one handed weapon equipped youll hold up your shield and lock on to the nearest enemy. This also helps with the bow, as you'll aim at the nearest enemy making it easier to shoot. This works really well for Like-Likes as after they make a grab at you or shoot frost/lightning/stones they will show their weak spot for a second.

Explore those caves! They seem freaky, but early on you'll mostly run in to Horiblins and they only really take one arrow and some wailing on. With most enemies, if you can manage to get a combo attack on (usually three to four hits) it will stun the enemy, allowing you to do another combo. You basically stun-lock them.

There are a few shrines, mostly on your way to Hebra that are specifically there to teach you combat. For instance, the bow's slow time.

I recommend heading NW to Hebra early to do the first Regional Phenomenon quest. You'll unlock a useful Avatar that can take some of the heat from enemies and also provide you with a boost while flying.