Some activities I can do outside in my yard?

I'm 15, I have to watch my 6 year old brother every single day so I can't go anywhere, and non of my friends live near me. We have a trampoline, but outside of that there's nothing to do outside in my yard, and I HATE staying inside during summer, but idk what to do if it's just my and my little brother outside... Please suggest some possibly fun things to do