There's being able to shoot well and there's being able to fight (defensive or offensive) using a gun, these are not the same thing. You need to get more clear in your mind what you want.
Further, training with good instructors is going to cost you. Plus you may have to travel to get to them. Skills must be developed and are perishable. It ain't going to be cheap.
There are also bozos claiming to be instructors who can't teach and/or teach poor material. Some have good personal skills but can't teach, some are just idiots, even those with 'credentials' or 'experience'. Some are good but what they are teaching may not really apply for your situation. There are also things which you should learn but that most shooters think does not apply to them.
For your very first teacher I recommend Massad Ayoob. Whether you learn your techniques from him or elsewhere, you need to learn some law and how it applies to deadly force. He is the best at that. For a 'warm-up' get his classic book 'In The Gravest Extreme' for about $15. Easy reading for the average person and an 'eye opener' for most people. Most people 'don't know what they don't know' and much of what they think they know is wrong.