Hi! I was wondering if anybody had any tips for me....?

You're a beginner!!! It's totally understandable to be excited!!! First, jeans are best unless your have equestrian breeches/tights because they have great natural gripping. The boots you describes will be fine unless they have heavy tread. Hate to break this to you, but you might have to be led. Just tell them that you've been researching and you've ridden by yourself before, and see what they tell you. They might start you with being led in your lesson, then if you do well with that they might let you ride by yourself on your trail ride. When you try and catch the horse, slip the lead rope around its neck. The it will be easier to get the halter on, PLUS your hands will be more free. Hope this helped!!! :)