Ponds are great! But you'll need shading windblocking trees. Mosquitos are inévitable but you can go out to other ponds and bring mosquito eaters over. And plants. Bats eat tons. It's always complicated to get a balanced system going.
When i came to this house i needed a mosquitonet. There was no pond. Now the system's balanced with all the biodiversity i could get for cheap and a smallish pond with liner(4000 litre) and i sleep with open window.
We have no poisonous snakes, so that's tricky to say something sensible about for me. They're nice snail eaters here that are afraid!
Frogs can be horribly noisy. I put fish in but fish that don't eat all the plants but female frogs just don't lay eggs. Just some older boys come in my pond to chill.
I never fed the fish, water's clear as can be. House gutter run off goed into 1000 litre tank, overflow into the pond. I feed the pond over dry period with the 1000 litre.
The bigger the pond, the bigger the problems, start small! Also not such a drama if it's just no good idea or possible where you are. But it is if you got a lot of money invested.