Mounts for noobs?

[MuseTraveller]

The Elemental Ponies from the extreme trials are a good choice. People often farm them in PF and you need minimum level 50 to join those.
You still need to unlock the fights however which will require going through the patches after ARR to Heavensward.
You can also unlock the beast tribes and do their daily quests. Eventually you get a mount from each tribe as a reward but it will take some time.

[Avatre]

You can also unlock the beast tribes and do their daily quests. Eventually you get a mount from each tribe as a reward but it will take some time.

These ones also help you to unlock crafting materials if that's your thing. Along with another way to get items for the Heavensward relic if you decide to do that(though you can farm Poetics which is rather quick these days).

Most mounts come from either Mogstation, extreme primals, collector's editions of the game/expansion, or from achievements(PVP/Mentor being the two that come to mind - PVP has 3-4 mounts I believe, possibly more)