Horse shopping!

I'm basically horse shopping for the first time! I've been riding my whole life (mostly western, english very recently) and owned for several years now (two horses) but since we purchased both of our horses from people we already knew it's pretty much the first time really shopping. I'm buying a new horse because I've grown too big for my horse and also am now starting to get into jumping and it's definitely not the "calling" of my little slow and steady trail horse. So I'll be looking at a lot of thoroughbreds and tb crosses and I'm very excited

Tomorrow my trainer and I are going to look at some horses for the first time and I'm pretty nervous and probably looking way too much into this but I was wondering if I should go in breeches or jeans. Is there any unspoken rule for or against either in this situation? I feel silly asking this but I want to give the right impression. I'm pretty sure I will be riding, but not 100% sure..I'd ask my trainer but we've already called her a million times and I don't want to bother her to death as she's very busy..but I can't help it!
I feel just like a beginner all over again!

Thank you and wish me luck!

If you are looking at the horse to buy you are ALWAYS going to ride it. I would wear a nice pair of breeches, and your boots. Good luck!

Oops, I'm sorry I worded that wrong. I meant that I wasn't sure if I would be riding on the first visit because I know that some people prefer that you ride on a second or third visit so that a lot of random people aren't coming just to ride their horse for free. Sorry about that!
But thank you!

I expect to get on the horse the first day I see it. I am also horse shopping and for quite a few of the ones I'm interested in I'm driving 3-7hrs to go and see. If they don't let me on the first time, I'm not going back.

Also, I usually go in jeans and put on 1/2 chaps. But I'm trying out QH prospects, and a lot of the English horses are ridden in a western saddle until they are in the show ring or going over fences, and I hate to put my nice boots in a western saddle.