Training usually takes weeks or months to become certified, and you'll need at least one homestudy plus a background check. All this varies by state, but I've never heard of a state where these things weren't mandatory to some extent.
So most likely you won't be able to care for this littel guy, but it is a very important thing to do, and I hope you keep up with it.
I attended all the trainings, and they pulled out on me at the last minute because I'm a single mama and I work nights. If I worked days, it'd have been cool.
Here's a foster parent message board, they can answer many of your questions.
PS-Not all children in foster care are available for adoption. Actually, the majority aren't. The main goal of foster parenting is to provide a safe and loving environment for the child while the parent gets back on their feet and is able to be permanently reunited with their child.