Batter keeps draining and radio issues

[Mrsrinehart6769]

Chevy Silverado 1500 . Year 2015. 
 

for a few weeks now once a week my battery drains completely. Plus for few months when I start my truck the radio and sound doesn’t work. I have to restart the car 3 times before I get sound .

this morning I drove it for 10 minutes turned it off and then it wouldn’t start again battery drained. 

 

dealership keeps saying bring it in sounds like computer failure doesn’t to me but I figured I’d do more research first