Let me try to clear up any “grass is greener” illusion you have, 'cos it will not serve you well.
You tried one PuG raid? One? And it failed? There’s a Preach video where he’s anonymous on a fresh account, trying to raid with a PuG. It didn’t go well - and of course as a world-class player, he would have been a major asset to the raid. Were you a major asset to the raid?
PuGs can be, and mostly are, pretty bad. For BOTH factions! Standard advice is to get a guild or community.
While Horde are more active, and therefore it’s easier to get groups, Horde is not a magic bullet for solving your progress ambitions. People can and do make great progress on both factions.
By all means, make a Horde on Draenor or Tarren Mill, where the action is, if you want to. Levelling has been so nerfed that levelling is not a thing any more.
But as always the keys to success in progress are:
- Git a group and
- Git gud
not necessarily in that order.
When it comes to gitting gud, Teh Interwebz are full of information. Finding a group that is suitable for you, OTOH, is the hardest thing in WoW. You need to find people of about your skill level or a bit better who actively want to do content at about the same rate and at the same times you do.
These two communities have a good reputation for newcomers to raiding and M+
Alliance: (Alliance) Scared of Dungeons EU EN
Horde: [H] Zen Horde - Chilled PvE Community
and The Fail Train Discord is available for both factions:
Horde gives you more opportunities, but it’s not opportunities that will hold you back, because there are plenty Alliance-side as well.
It is the effort you put into working with a group, and into improving your play, that will get you into raiding and M+.