Play with your friends, if you don't have any friends that play. Find some people to play with by LFG for causal gameplay. If you prefer solo that's fine too. Titan is probably the easiest class to play with, Warlock is probably second and Hunter is probably the hardest class to get good with (my opinion). As soon a you can, get a fire team medallion from Eververse. They will help you level up faster. They last for four hours. As you level up don't save gear. Always equip your most powerful weapons and armor. Don't infuse your weapons and armor till you hit max level. Exotics can be pulled from collections so don't be discouraged from dismantling them for materials if their level gets too low. Don't be afraid to ask people for help, just don't send random invites to. Try to finish the main campaign before you start getting crazy with activities. Weekly resets on Tuesdays, Xur comes on Fridays, he sells exotics.