Hi Megan 🙂 I advise you to take time to walk a lot at the beginning of your training without holding your reins tight at first, ask simple things like halt, turns...
When you feel your horse is relaxed, ask to trot, with your reins loose, just asking your horse to move forward, turn. Then you can ask some transitions, using mostly your voice and your seat, and if needed your reins but with smooth actions.
Same for canter, once you feel your horse is relaxed you can canter, with the same work as before
Keep yourself calm and relaxed, your horse will feel it!