Hi Slz,
Just some more info for you. I too was young when I was approved. I don't think age matters, only your disability.
You will also get a separate check for every minor child until the age of 18 years.
Again as stated by someone else, you can start the paperwork by going to the ssi.gov website and read all about it there and probably download all the necessary paperwork from there.
I do remember meeting with someone at the SSI office to start everything rolling plus a phone interview at some time as well.
They asked about my husband's income, to see if I qualified for financial aid to help out as well but I told them that I wasn't in need of that, and was only hoping to collect near what I was receiving from not working. We were living on two incomes and I was just hoping to contribute back to my household what I was losing by not working so I didn't even go into my husband's financial income. So I think if your husband does not make enough or not working there is also more help out there for you.
Oh another thing. If you are able, you are allowed to work some hours and receive a certain amont of money but there are stipulations as to how much.
Best wishes for wellness.