I've told this story before, but repeat it FWIW:
I've got a bunch of books on riding. When I tried to figure out how to cue the horse to canter, it seemed to all be, "Push the right side of your hip here, turn your left ankle inside out, breathe deeply 3 times, and fart gently, directing the gas out to the left side of the horse..." Don't know about you, but I never thought of my hips as having independently moving sides...
I was taking western lessons at the time, so I asked the other, more experienced riders in the lesson how to cue a horse to canter. They all looked at me kind of odd, and finally one replied, "Kick harder?"
There is a lot of truth to that in how I cue my horses. I usually trash talk to them first: "You want to canter? YOU want to CANTER? You're just a nag...you aren't strong enough to canter!" Since my horses understand my eccentricity, they get a bit excited. Then a firm squeeze with the legs, and we're off! And since a lot of our cantering is on a trail, I don't worry about leads.
That obviously isn't 'proper' riding. Imagine watching a show, WP or dressage or ANY show, and hearing the rider say in a loud voice, "You aren't HORSE enough to canter!" - and then cantering after the horse got excited. Any judge that didn't laugh would probably toss a beer can at me!
How much English and Western riding differ depends on the style of both. Western riding includes the old style cowboy approach, which can drive modern riders nuts:
I often direct rein, which I don't associate with western riding. How much slack, if any, in the reins depends on the horse - Trooper gets a lot, while Mia prefers very little. But then, one of the reasons I consider myself to be a western rider, even if I often use a *******ized forward seat and an Aussie-style saddle, is that I'm only interested in what my horse and I like.
I also find, as an older rider who took it up late, that a lot of the instructors I've met seem to focus on how they learned when they were 10 or 12, rather than prioritize things based on how a much older body bends, moves, etc. I think an older rider benefits more if you work on one thing at a time, or accept that some things won't happen right away. After 5 years of riding, my heels aren't as far forward and my toes aren't quite 90 deg out any more, but I wasn't physically capable of riding in the 'correct position' at the start. Can't now either, and one foot sticks out sideways more than the other. Finding an instructor who appreciates both the different capabilities of an older body, coupled with an older mind that understands that a fall hurts more as we age...that's tough. They exist, but they aren't hanging around everywhere.
< / rant >
BTW - Good luck!