I have been interested in 3D printing for a long time but now the prices have come down as it has become more popular I decided to take the plunge and purchased a Creality Ender 3 Pro. This is classed as a budget printer but has very good reviews. You do have to tweak it a bit to get the best out of it and you do have to build it.
I think building a printer is good though as you get to know the parts and the way they all go together to complete the printer. There are numouras YouTube videos of building this printer and I would suggest you watch them and then take your time to make sure everything is level and upright.