Welcome!
Have a good peruse of the docs here: monome.org/docs
I would suggest having a look at monome sum, its a good self contained primer for some of the wonderful things you can do with your new grid.
Once you have your grid if you encounter any specific difficulties getting things running then search the forum, you’ll find solutions, advice and discussions aplenty.
Failing that let people know, you’ll find many knowledgeable and generous souls around here 