In order to move up from where you are at, you'll need ~45 wins total, and they need to come from winning seasons mostly. Making the playoffs will obviously help. Getting hired at D2 is very easy, but it gets harder as you go along.
Once you reach D1AA (in about 4-5 seasons if you do well, probably closer to 7-10) you'll need ~80 wins minimum to move up to D1. The fastest I've ever seen anyone reach D1 was about 7 seasons total, from when they began in D3. Luckily for you, Rice isn't hard to get to, so you won't need a crazy strong resume for them.