Overall fitness and continued improvement are my goals. I would like to hold my own with group rides locally. My rides and group rides are typically in the 20 to 40 mile range.

I appreciate the responses that have been provided. Thank you.

I like the shoe pedal idea followed by a trainer. Also, you may want to check if there are any cycling clubs in your area that fit your goals. I wanted to race and joined a racing team. I learned a lot by observing what other racers used, how they trained and went to meetings where we had speakers that discussed a wide range of topics. Clubs that focus on other aspects of cycling may be available locally as well and clubs / teams may have sponsors that offer deals on equipment and clothes.

UCI world tour pros are an interesting breed. USA does not have many such that most of them are from Europe and the former Soviet Union. I started my race training with coaches from Belarus who formerly ran the National team before immigrating to the US. They had a cycling gym and I had to show up twice per week for supervised indoor sessions lifting weights and riding on the rollers / trainers. In California the weather would be great and I would be indoors.

Their two most famous UCI world tour pros that they coached were Vasili Vasilyevich Kiryienka and Kanstantsin Sivtsov who both raced for Team Sky. Vasil won the time trial world championships a couple of years ago. At the Sky camps in Mallorca, they would train on the rollers in the morning and ride with the team outside in the afternoon with a nap in between. In 2014, I used the same coach and he wanted me to do two workouts per day - trainer and road. It was too hard. Maybe today, I could do it.

The other thing to understand about former Soviet Union cyclists is that cycling was a way to escape the oppression. If one made the national team, one was setup with benefits. If there was success, one was set for life with perks. So much like Cortez, these cyclists burned their ships such that there was no going back and they worked very hard because failure was a disaster.

So if the coach said, you are on the trainer 6 hours a day, well, you were on the trainer 6 hours per day even if it did not make any sense and there are better alternatives.

One of the first workouts I did was 10 sets of 10 through a Russian torture circuit of weight training to build strenght in the pedal stroke and then lower cadence intervals on my road bike set up on the trainer. I rode the trainer a lot and it caused me to HTFU a lot.

Thank you for the additional information! Seemingly lots of good practical information!
Shoes and pedals soon, then a professional fitting shortly thereafter. These would be the first things on the agenda.