Tanking, at least early on, is piss easy. Use the ranged attack from your level 15 class quest to pull monsters (Only two guildhests are at level 10, other than that all group content is 15+), use your AoE ability (Flash for paladin) to get some initial hate on the enemies (a good rule of thumb is to do so once for every monster in the pack), then use your enmity combo (Fast Blade into Savage Blade, then into Rage of Halone once unlocked). Cycle through them to ensure you keep hate on everything (You can also mark a kill order, but many players ignore this). Alternatively, if you have more than 3 monsters just keep spamming your area of effect.

That's the bare minimum you need to know. Do that, and you'll be able to tank all your dungeons as you level up. There's more you can learn, such as how to maximize your damage capabilities while keeping hate, how to do large pulls to clear dungeons far faster with AoE damage, and the more advanced tricks necessary for trials and raids (Which is something every role needs to learn on a fight by fight basis). Still, if you manage to keep hate on everything, and keep your gear decently leveled, you'll do well enough to keep your party happy.