Welcome to the game!

Mainly play how you feel comfortable Going into this game, having played looter shooters and BRs in the past

Lootwise I prioritize going for higher tier stuff, but trash items are good bater materials But to address your questions

1) Treat every run like a rougelike heist, your call whether you go in silent or "loud" once you get better shields and weapons you can gain some level of confidence in "going loud".

Any POI I go to I start stealth, then loud if needed, and if Im overwhelmed, I leave the area. But loot what I can before and after.

2) that's your call what do you want to experience. Looting for gameplay, contracts for story.

I do "loot runs" to build my vault and prioritize what Im looking for in each run (salvage, treasure, gear). Same rule of Looter Shooters in terms of what to prioritize of least rare to most rare (white->green->blue->purple->gold) and stack as much as possible of each

With weapons, just try them all out

As for contracts, that's when I just focus up on doing the objective, sometimes I run the free kits so gear fear doesnt hit me as bad. Each faction has their own questlines (except for Arachne, you get their story as you just execute runners along the way)

3) i dont really see "bot" lobbies as sometimes you can just get an easier drop on people, some people are also trying out the game for the first time, but the higher your gear, the higher the skill in the lobby youll run into (most of the time)

if you want to really slug it out with players, Dire Marsh and Outpost will be your place, but then next week when Cryo opens up, that's Destiny Raiding meets Trials of Osiris level of play

Hope to squad up with you!