Hiking gear advice for bigger girls

supergirl6

This summer I'm heading off to Sequoia and Yosamite national parks in California with a friend. I'm not a hiker, but I want to be and even though I'm still pretty big (300 lbs) thanks to a personal trainer and hitting the gym 5 days a week for months now I'm in way better shape than I have been in for a long time. We're spending half our vacation in the parks and I need to get some gear before I head out there.

How do I choose good footwear? We're not going to be doing anything super intense, but I don't want to wear my Brooks tennis shoes either. I have no idea how to even pick something or make sure they are broken in before I get there. Any advice you can give would be much appreciated.

Also, can anyone recommend any stores for buying clothes to wear that carry bigger sizes? Online is fine.

I am pretty sure this is the first time I've gone on vacation that centered around being active. I'm so excited and nervous but mostly excited. I absolutely can't wait!!