I'd start with the singing lessons. Cos apart from anything else they will start to increase your confidence.
Going from living on the margins into the limelight can be terrifying at points - so much so you want to step back into the shadows. It does get easier the more you do it though.
As long as getting a job ASAP isn't financially a must, then I'd take the time to look around and choose the best one for you.
Also make a list of all the other things that you've ever wanted to do - from the tiny to the huge. Some won't be achievable, some will and some you may change your mind on. But it will give you some ideas to pick from.
It might help to imagine the person you've always wanted to be - what kind of things does that person do, or take part in?
Unwards and upwards and I hope everything is as fabulous as it can be.