If u want it permanently on, u have to turn off push to talk in the settings. Otherwise, u just hold down whatever ur push to talk button is (idk default, as I use discord for all my voice chat) and speak. Its only fireteam chat tho, i dont think u can speak to people not in ur party
also, not to rain on ur parade any harder, but if ShinyPants is ur battle.net tag, ur never gonna have anyone add you. U need to include the # and numbers after ur name. For instance, my name is Im2shady4u13. But unless i tell people Im2shady4u13#1755, theyd never be able to add me
Umm... on discord you can find servers(the same as groups on facebook) where people get chatrooms(text and writtens).. just like this one there are a lot of groups(servers) for destiny 2.. some are also for a single clan. You can join a lfg server which has got lots people looking for an activity. I dont know the link and im not on my PC so any member might give it to you