If you go with jumping, then you'll start with flat work until the instructor deems that you're ready to jump. Ideally, jumping and lower level dressage have a lot in common. Both want the horse balanced and engaged; both require the rider have an independent seat; and both require the rider be able to control the horses body (example: shorten/lengthen strides).
Even if you choose jumping to start, it'll be months before you go over a jump. Unless you get a "point and shoot" instructor, which is not good. Jumping requires a great deal of rider control over their own body. Don't expect to start jumping within the first six months.
Dressage has the benefit of teaching the rider how to use their body effectively, and each part of your body independently from the others. I like the German idea of starting everyone in dressage first to give them a solid base of skills. Then the rider can choose what direction they want to take.
And there's nothing saying you couldn't take dressage lessons and jumping lessons at the same time (other than costs). I'd focus on dressage for 6 months first, then you'd be more comfortable in the english type saddles. To start with, I'd look for a general purpose saddle to use for dressage and jumping lessons. Don't buy a dressage saddle until you're certain that's the path you want to take. You don't need a dressage saddle for the lower levels.
And Don't go with a lower-level dressage trainer. They lack the big picture view that a higher level trainer has. Some of the fundamentals end up being ignored, or there are gaps in their knowledge. You'll never be any better than the person you train with. Spend the extra money for a qualified instructor who's gone through the levels. Even if you never plan to get past the very lowest levels, at least you'll be learning correct basics. I have had so many bad experiences with people claiming to be low level dressage instructors, and they know absolutely nothing about dressage. It's not even worth the frustration and wasted money. Pay the higher lesson fee for a knowledgable trainer. And make sure they've trained through at least Fourth level. They are not dressage instructors if all they've done is some training level, or never even shown dressage, or all their students are still riding Intro (or Training) Level two years later. They better have at least one student who's training Second or higher. Otherwise, you'll end up a worse rider than you started off as.
The USDF.org site has listings for certified dressage instructors (listed by region, then state). If the trainer is certified by the USDF for lower levels, that's okay. There are also GMO's (USDF group member organizations) all over that put on shows and clinics. Going to the events would be a good way to talk to people about who they train with, and find out which trainers have good reputations.
CenterlineScores will allow you to verify scores for potential instructors. Take the scores with a big grain of salt. Also, look up their students scores to see how well they do. Scores in the 60's are fine some high fifties would be fine as long as it isn't the majority. You can cross reference the scores from centerline scores by looking up the shows. If everyone in that class scored low, than a low score isn't necessarily bad. But if everyone scored high 60's and the trainer got a 55%, then that's bad. Posted via Mobile Device