Rookie glider question
Do you mean just getting gliding at all, or getting the higher mastery tiers?
For just getting gliding:
Go to your Hero Panel, the Story tab. Select the HoT story and begin it. Go to the south entrance to the Red fort in SW, enter the story, and do it to unlock Verdant Brink, which means doing the first chapter of HoT PS. Completing that puts you in the start spot for VB and gives you one mastery point.
Now click the little square at the right end of your XP bar, or bring up your Hero Panel and select the bottom tab, masteries. You should have Gliding marked as what you are training. Make sure of this by clicking on that mastery.
Now go earn XP in the HoT maps. Explore, do events, gather plants/ore/wood. Watch your xp bar. When it hits max, click that little square again. At the right side of basic gliding you will see a button you can click to train it, it will say 1 to let you know it will cost 1 point (later tiers cost more points). Click that.
Now you can glide! Just jump off any height and keep your space bar pressed.
Short form: Do HoT story first instance, select gliding, get xp until you can spend your point on gliding.
If you mean higher tiers: Make sure to select the next tier as what you want to train. You can hop over to other mastery lines any time you like but it makes most sense to power through one line completely. Note how many mastery points you will need to buy that tier once you have the xp invested in it. You will need to gather those via achieves, adventures, mastery point communes, etc. If the only thing you are training is gliding (though really, you’ll want bouncing mushrooms pretty early on as well, and probably vendors too), you should be easily able to gather enough points to get all the way to ley gliding just through normal exploration. Each higher tier will take progressively more XP to max.