Apple watch refusing to download apps.

I am a 13 year old with a Apple Watch SE managed by my mom. I just received it recently and it does not want to download any apps. I had restarted the watch and my mom restarted her phone three times now but it does not want to download any apps. Every time I hit the download button, it tells me that I need to sign into my apple account. So I do, I double tap to download, and it does absolutely NOTHING! It does not tell me that it is even downloading and it doesn't show up on the apps page showing that it's downloading. Please help.