Congrats on your new harp!
From a teachers perspective, things I watch with my pupils when they go over to a pedal harp:
Posture – as you are moving to a larger and heavier harp. Watch how you sit, adjust your chair to an appropriate height. Sit straight, and make sure you are not taking too much weight on yourself when you tilt the harp back.
Tilt the harp back, find the spot that it balances, and adjust the height of your chair, and move to a position that you are taking a bit of weight on your knee to keep it at is natural balance. You should take no weight on your shoulder and only a minimal amount on your knee.
And try not to over do your practise at first, do not in your enthusiasm go beserk and do too much practise. Take breaks, remain relaxed and do not try to play too loud.
You need to remain relaxed and avoid tension. the string tension on a concert harp is usually higher and requires more strength then a lever. Build it gradually, and take oodles of breaks after say 20 minutes.
Congrats and hope this helps,
Curls.