I would recommend starting at a zoo, inner-city park/lakes* and village ponds* – these are usually teaming with life that readily accepts people, so you should be able to get close enough to them without too much trouble. These are also great places to practice your camera settings, distance to subject, field of view, depth of field, auto-focus settings, selecting natural-looking backgrounds, stalking your subjects etc) and once you have got the best from these locations it’s time to find more challenging targets!.
*NB: I would recommend shooting birds on the water from as low down as you can get, this seems to produce a much more natural and impactful image.
It is very easy to set up a feeding station in your garden – select a location where you can get close to your chosen camera location/hide. This could be a shed, a suitable window from your house, a tent/photo hide (easily available on Amazon etc). Work out what time of day you are most likely to be able to do your photography and set up the feeding station with the sun behind you. Add plenty of natural looking perches in the feeding area with a neutral background (hedge etc) if possible – try and keep a bit of distance between the perches and the background so it is much easier to throw the background out of focus. In a few days you will be amazed at the variety of birds that will start to appear.
For wild birds and animals in their natural location it starts to get a bit more complicated. Most of them have superb vision and most animals also have an amazing sense of smell. When walking about normally they don’t seem quite so wary of people, but it often seems that the moment you start creeping about with a camera they can get very suspicious! Try not approaching the subject directly, slow down, keep as quiet as you can and don’t make any sudden movements. Another option is to find a good location and wait, once you are not perceived as a threat, they will relax a little and usually start coming closer to you. Also try not to look directly at them and this is taken as threatening behaviour as you are now acting like a predator. Oh, and switch your phone off!