That's really commendable.

It'll be easy to bore the kids with tons of details about variables, loops, and structures. At-risk kids are usually less curious and more interested in usefulness (I think).

First, get their attention by giving them the fastest route to a simple working program. Basically just show them that they can make programs that can be useful, then help them build by being a local expert.

You can teach variables, loops, structures as your students need them to make their programs work correctly - that way they'll have a good reason to want to learn.