You are in the right place if accuracy is what you seek. Smith & Wesson is the king of good triggers in production hand guns. A good trigger is essential to accuracy as mentioned above. A lousy trigger makes accuracy impossible for me, while you can learn most triggers, a good one makes life much easier.
Dry fire is essential, after 65 years of shooting I still dry fire as much as I can.
Coaches are a dime a dozen, but good coaches are hard to find.
Books are also plentiful, one of my favorites is "The Pistol Shooter's Treasury" by Gil Hebard. There is nothing in this book that will steer you wrong. The information will also be beneficial in knowing what coaches to listen to and those to ignore. Mr Hebards advice - "Experience is only a good teacher when you are a good student." is one statement that I still hear. By your questions I feel you are on the way to being a good student.
I wish you good times.
The book is out of print, but you can find used copies on the net, Abe Books has 3 available, it may seem expensive, but I assure you it is worth it.