I bought the sandbox & the swing but my sims won't use it, what do I do?

Probably the Sims can't access it. The sandbox has an entrance on one side of it and the swing has to have room on both sides.

The sandbox and swing is for toddlers only. Like in the sports center for pre-teens, theres a sand box in the back for toddlers

In the swing set just touch the swing set I don't know the sandbox

You need to have a toddler first then, your sand box has a side which is dìffrent, you need to have that facing a place your sim can walk too. Then you click on the toddler and click on the sand box and select one. As for your swing set you must have it facing a clear place behind, at the front, and at the sides, then for an Adult and pre-teen all you need to do is click on the swing set and choose an option, a baby can go on the swings, BUT for a toddler you must have an adult there and the toddler, go on the toddler and make him / her go on the swings

I have clear space all around my swing set and I even put an Adult next to it but when I try to make my toddler swing on it it I get the noticifation saying "an adult is required" what am I doing wrong?

There needs 2 be enough space on each side of the swing set for your toddler to use it. You may need to move other Objects such as trees. Hope this helps!;)