Route 395 Bridgeport to Bishop

In June will be driving 395 and have a week to spend there before heading to Las Vegas.

I think we'd prefer a USF campground or BLM, but really we want to be next to water for fishing, and no where crazy busy. Any suggestions around the Bridgeport area, perhaps one of those near Twin Lakes? This will be over a weekend.

Then a 2nd location further along, around Mammoth Lakes? Or Bishop? Again, on water for fishing! Don't love really hot weather (unless I am in the water!) or mosquitoes. This would be Tues-Fri. 

Then after to Vegas (kids soccer unfortunately). also, any specific route to take/be aware of from there to Vegas?

Also, if these have bike trails (not mountain biking) that would be amazing.

We are towing a 31' travel trailer. Thanks!