There are plenty of approaches you can take depending on the type of wildlife you’re interested in. For example, to attract birds, all you need is a suitable bird feeder and the best bird seed you can find — this website can help you with the latter. Birds will go where the food is, and you can make the environment even more friendly to them by adding a birdbath and maybe even some birdhouses.
Remember that a quality bird feeder should be designed to allow birds to eat while also keeping squirrels out of the seeds. Even if you want squirrels in your garden, having them eat off the bird feeder is a bad idea. They’ll drive the birds away, and they’ll likely even end up breaking the feeder.
Speaking of squirrels, you can get them to visit your garden by opening gaps in your fence to make it easier for them to come and go. You can also encourage them to show up by leaving food for them in feeding bowls and leaving out hollow tree trunks they can use to hide in or build their nests. Squirrels will also appreciate having a tree they can climb up and down on.
Bees and butterflies are also exciting types of wildlife to have in your garden, and attracting them is as easy as planting the right flowers. Or even just having flowers at all. Of course, what attracts one will often also attract the other, but if you’re hoping for more of a given type of insect, you can look up which flowers in your region are particularly good at attracting that insect.
Finally, you attract toads and encourage them to stay by providing plenty of moist hiding spots for them and ensuring there are still enough insects in the garden to serve as food for them. Having a water fountain installed can also help.