Every year you should have a clear out of your old makeup as most products don’t actually last that long once opened and can cause harm to your skin.
You can check the shelf life from reading the label and it will have a picture of an open product with a number in the middle. The number is how many months it lasts once opened.
You will probably end up with not many products left, but the ones you do have are likely to be your everyday products.
The rest of the old makeup can be up-cycled in many ways which you can research in Google but what I tend to do is give my boys a paint brush each and some paper and let them loss with it. They love it as they aren’t normally aloud to touch my makeup.