Most answered about AMC. AMC is the best of all for me. You need to find a test center, either your local school if they accept, a university listed at their site or private center like AoPS. My DS10 took AMC8 test thorough AoPS academy. Mathleague - You do not need a team, just register yourself as some home school online and then you can register your kid for the test near to your testing center. Now with covid all tests are online, if your kid is middle school level, the tests are still open.