Welcome to the server!
Ladies in the center of the lobby allow you to organize a party, which can be solo mode if you want, or multi mode. You can also set a password on your 'room' as they're called to only let people you want to join in.
To get to quests, there is a lady behind a counter in the room you originally spawn in (once you are in a room). Solo mode quest unlock as you complete them. However, unlike past versions of the game, instead of unlocking the next area's quests by defeating the boss solo, you need to complete the Government Quests. These are only available in multi-mode by taking the green warp to the presidents office and talking to momoka, the girl in the pink dress. You do not need more than 1 person for these quests, so if you want to do them alone, just add a password to the room and don't tell anyone what it is.
To go down to the planet into one of the free roam areas, take the blue warp. All areas are initially unlocked, and increase in difficulty as you go down the list.
Don't be afraid of other people on the server. The vast majority are amazing people and many are willing to help. Either by taking you through an area or by donating old gear.
I hope you enjoy your time here. If you ever need anything feel free to send me a Private Message.