I've been inactive for a very long time and would like to get back into it. However I know nothing anymore.

What is the best equipment?
What is the best team to run? I was using shadow, light, and air
Any battle guides you recommend?

for equipment+strategies for lg elites/bosses, Unstaeble's guide is pretty good (although it lists only evoker/pyro for light healers, when I'd always say those or illusionist/lightbringer, in whatever combination)

Shadow/light/air is a perfectly common build- what a person runs will be what works for them (though it's always worth testing other things out at least for a little) and the tank/healer/attacker setup is the most common one for a reason, though not the only one.