I personally think you can have a sparrowhawk or a Kestrel for a first bird, BUT...
If you want a accipiter for a first bird, you must have a lot of practical experience. Which you can only get by handling birds of prey by another falconers, if you've got the experience you need you can get a sparrowhawk or kestrel without any problems.
Birds that can be seen as "first bird" I think there aren't first bird, they're only less difficult birds are more like Harris hawks but then again they can be more trouble than good