I use promo only and franchise record pool.
Promo only (
https://www.promoonly.com/) has a well curated selection of mainstream pop and hip hop.
Franchise record pool (
https://www.franchiserecordpool.com/) has most of the underground stuff that teenagers like. It's also good for reggaeton and soca.
Beatport is good for EDM and allows you to connect your DJ software to their catalog if you have a subscription, but I don't recommend doing that.
I recommend keeping open tabs for a service that sells single tracks (I use Amazon), YouTube and a site that rips YouTube to mp3. Kids will inevitably want music that you've never heard of and can't find anywhere else.
One final word, if you're playing a grad party make sure that the parents want clean versions before you play them. A lot of parents don't care, and the kids are almost always going to want the dirty versions.
Lmk if you need anything else.