I coached basketball for a few seasons - boys 3rd and 4th grade, 4 seasons in total (fall and spring twice).
The key is this - keep them moving in practice. If you can get a parent to assist, that's great. Have a flow that is consistent with each practice, always have 1-2 things you want to focus on ... review the last practice drills and then end with a scrimmage.
I'd always start off with 5 minutes of running, jumping jacks, etc. I'd end it the same way. If you have to repeat yourself - pushups or running, the whole group - not just the kids goofing around.
I liked 90 minute sessions compared to 60, but you may not have that option. Keep things basic early on ... ball handling drills, dribbling, focus on control and confidence. Basic passing drills (bounce and chest).
I'd always use cones on the court maybe 3 max and have them run drills from one side of the court, ask them to dribble with control while running/jogging to certain points - practice shooting from the cones. Practice stopping at 1 cone, passing to a player at another cone and then they shoot.
Depending on the level of skill - you'll have a mix, but you need to find out who will be your point guard - you may want to mix it up a bit, but you need to know who is going to control the ball - then move kids around and let them know where they should be in position on the court.
There are lots of great basketball drills on YouTube - just spend some time looking and you'll find lots of great ideas.
The kids love to scrimmage - so I would always say "if we have a great practice and we focus, we'll end with a scrimmage". Use it as a reward - USE YOUR WHISTLE! You have to show them you're in control - be firm - but coach them up, realize that some of the kids will feel out of place or not confident about their play compared to others.
I don't think it matters how much you know or don't know... you have to build trust with the kids, if they don't trust you or respect you or think that YOU believe in THEM - you've lost the team.
It can be a lot of fun, just be organized and make sure they have fun - celebrate the successes. Don't make a big deal about screw ups.
Most teams (as I learned) will play ZONE defense 95% of the time... realize this and get them to work on their jump shots.
Passing is key - but INCREDIBLY hard to coach, you have to make it a habit. Don't play favorites with kids ... don't put 1-2 kids on a pedestal, they'll never earn the respect of the team. They should earn their playing time and that's by hard work in practice and being a great teammate...
Good luck - it's a blast!