Welcome to RoR!
First of all I'll link you what I think is one of the best newplayer guide youtube channels, by Hazmy:
https://www.youtube.com/watch?v=qk0jjHu2kNc&t=4s
What makes RoR stand out from other mmos, is that you can level via pvp from lvl one. Either in open rvr lakes for your level bracket, or in instanced pvp matches called Scenarios.
If that is not your cup of tea, you can do leveling via question going from town to town and progressing your Career level. I would note, that progressing your Renown rank is unlocking pvp items, such as armor, weapons and accesories. Along with skill points you can spend to make your character stronger.
Questing, killing monsters, doing public quest and selecting influence rewards are still a decent alternative.
If you wonder what the time investment is for in the long run, then making a strong character building up a name for yourself on a smallish community, finding fun likeminded folks to play with, and doing endgame pvp content is what the majority will strive to do on RoR. But this is free to play, and whatever is fun for you, should be what you are doing.
If you need a milestone goal, here let me give you one. Find a class you enjoy. Play it in Tier 1 (1-15) and then try to find a dungeon group for The sewers lowlevel dungeon in Altdorf. That will give you a full lvl 17 set of armor, some blue acceories dropping from the mobs in there and maybe even a weapon.
