If you don't already know what AoPS is, it is a fun website that helps you increase your math knowledge. Art of Problem Solving has many fun games to practice math such as For The Win and Mathcounts Trainer. Here are some links to them and make sure to register for an account.
There are many other things to do on AoPS, and if you need any further assistance, just search it up!
Math Divulged has lots of YouTube videos and their own site for classes for math help.
Guidelines:
Make sure to not create multiple AoPS accounts because if you get caught your account will be terminated.
Choose your username wisely. You can't change your username after you register the account.
Please follow all the rules that are given on AoPS. If you don't, you will most likely get banned.