Here’s a few fundamental skills and checklist items you may want to consider:
If this is their first time playing the sport your child is enrolled in, we always suggest that you discuss the sport prior to their first day at camp. It’s important to provide them with some basic understanding of the sport in terms of the skills and what it would be like to play. Just the basics is fine, no need to to go into too much detail or rattle their minds with all the rules. Learning the fundamentals is very important and we take pride in making sure that will happen.
An important lesson a child should learn about participating in a sport is obligation.  Look at a calendar together and discuss how many hours of each day they will be at their camp or clinic. If you're playing on a team, your team is counting on you to show up- you all need each other.
While equipment is important, it is not important that you go out and buy brand new expensive equipment- especially if your child is just trying out the sport. There’s nothing wrong with starting out with used equipment.
It is important that you practice with them. Rebound when they shoot hoops or play catch so they can practice their new skills. This will show them your support.  We find that parents who participate with their kids have much more enjoyable experience overall.
Good luck on your youth sports journey. It really does not matter if they have ever played a sport before, if you get them playing and having fun, they will fall in love with being healthy and active, and this will keep them healthy for life.