I would love to find a good instructor and I don't mean a certified NRA instructor. I mean someone that can diagnose what I am doing wrong and what to do to correct it. I don't need someone to tell me what a magazine is or how a slide works or what the difference is between fixed and adjustable sights. Some of the NRA instructors I've seen are no better shooters than the rest of us, they just spent the money on the video and work book so they can be labeled "certified".
I wanted to think about this before responding. I guess the first question I have for you is this: Does the NRA basic pistol course or the instructors themselves promise to teach advanced or even intermediate marksmanship skills? Of course the answer is no, the course is intended to teach beginners the absolute basics and safety.
I have the certification in question, I took the time to get it for basically personal enrichment, much like my most recent college degree, a AS in Biology that I earned at age 60, well past the optimal age to make a career change. I had to take the NRA Basic Pistol Class, the one that I'm now certified to teach. The first words out of the instructors mouth was "we are here to learn basic pistol skills, not how to become a Master Class competitor. If that is your expectation then see me later and I will point you in the right direction".
Second of all there isn't any way to become certified that I know of by watching a video.
Since you admit that your skills are in need of improvement and you would "love" to find a qualified instructor to help you improve, may I ask what geographical location is it in the USA where there is literally no one qualified to help you reach your goals? It is very likely that an instructor that meets the qualifications; required to diagnose and remediate will charge considerably more than the basic pistol class charges and will probably take more than (1) 8 hour group session.
I personally don't "teach" the basic class but will assist another instructor if asked. On occasion a student will inquire about further instruction. I think the answer to that inquiry depends on what exactly the student wants to achieve. Last year, as a "B" shooter in SCSA, which is an intermediate skills classification, I took a 5 hour class with 4 other competitors designed to put everyone at a baseline of skills and attitude and break down each component of the cof. Then in detail re-start from the ground and build a plan for advancement. When I got home I had notes and ideas but my actual skills were unchanged.
Over the winter I used my notes to set up a practice routine and used the skills the instructor went over to set out to move up in classification. This I did but it took time and effort, a lot of time and a lot of effort. 3 other students in the class have not improved at all this year and in some cases shoot worse. Is this the fault of the instructor or the student? You cannot pay someone to give you skills but you can be presented the tools that will make you better but you need to do your part.
A basic pistol instructor doesn't need to be an expert marksmen. True they should be experienced enough to diagnose beginner issues like proper grip and sight picture. When I was taking the instructor class there was a portion dedicated to teaching a "mock" class of beginners and while the instructor candidates are required to demonstrate some kind of marksmanship skills it really isn't that difficult.
I live in a area where I can with ease employ several Grand Master classified and highly distinguished competitors that will for a fee (lets say $600.00/day) teach me the fine points of my favorite game. I know people that have done this with positive results. I know others that have done it with little to show for it. I have also seen competitors who shoot well, breaking one or more of the basic technique rules but still achieve a good score.
So what to make of all of this? My opinion of course but if you have already acquired the basic information and know what a slide is but want to get better then prolly the best thing you can do for yourself is define you goals and then set up a detailed plan to meet those goals. There are many books and videos that you can use to refine your plan but the main things is to realize that the best way to improve gun handling skills is to spend time, a lot of time, actually handling the gun. I don't know you personally but I think that if you want to improve yours skills and are willing to make a viable plan and diligently work at it then you should see positive results. Good luck and have a great day!