I put in a few ponds and surrounding gardens,I think that's about all you need to attract critters.
I'm in Florida though so it may be different than where you're at,but I got frogs within a week of putting in every one of my ponds . Lizards always come too but unless you have a really big pond,which you don't ,you're not likely to get or even keep turtles unless you fence it in after you pu turtles in.
Turtles can pollute your pond really quickly though so I wouldn't advise it,especially if you don't have any type of filtration system.
Moving water is a good idea,even if it's not filtered.
Good luck and enjoy