Ratchnick
Crowing
1x1 16 ga will be strong enough as long as you can keep out racoon paws, i don't know about snakes or rats as i have no experience with those. The easiest and cheapest way would be to use 4x4 posts dug into the ground, 5 should do it. Its same as installing a fence post, lots of u-tube videos on how to do that. You might look into aviary net for the top, might be cheaper.