For me, the hardest part was finding a game where I felt welcome. I have a few challenges to deal with before I feel that there's room for me in a game.
One is a learning disability; due to chronic pain my capacity for taking in new information is limited -- I can swallow down only so many game commands, setting lore, and background information in one sitting. Games with miles and miles of old history that you are expected to read up on and know before daring to join a conversation -- not happening. If your setting deviates that much from the canon universe, whatever that is, it's not accessible to new people.
Games with complex custom settings and stories that require lots of lore learning before playing are out (looking at a lot of novel or movie setting games here), as are games that require you to learn a ttrpg system (looking at the various WoD games here for sure).
Social anxiety is another. Games where you have to pretty get on your knees and beg in order for older players to notice slash recognise you are out. MU*s are social games -- don't make newbies exist in their own vaccuum for days if you want them to stay. At the very least return IC greetings.
I don't expect roleplay to get handed to me on a platter when I enter a game, but I have had the same experience many times when deciding that I can do this, yes I can -- you get a character through the app process and finally get on the grid, and no one responds to you. You walk into rooms and try to join a conversation and get flat out ignored. You see people who are somehow marked 'helpers' or 'newbie friendly' and send them a whisper or a page -- and get no response. After a few hours of that, I'm out. I'm not going to stay where I am obviously not wanted.
And obviously, the community needs to be tolerable. I've seen some pretty horrific things out there, although the MMO games tend to be a lot worse than the MU*s.
In the end I gave up on MU*s and MMOs alike. I got dragged back in this fall by @JinShei whom I used to play with elsewhere when she was opening her new Discworld themed mush. I am grateful for that because it's a setting I know very well, Ares is ridiculously easy to learn and use, and since I was there from the start, I don't need to bang on doors to get the older players to acknowledge me (though I make a point out of trying to greet guests and newcomers the way I've often wished someone would greet me on a new game).
Amazingly, it looks like my tale of woe got a happy ending.