250 should be fine and congrats on doing test-only for your first cycle -- both great ideas IMO.
Make sure you are eating well, sleeping well and training well before you start. Ideally, be pushed-up against all your existing plateaus before your first shot. Then use the gear to blow past them.
FYI, you are pretty light by BB standards, but that doesn't mean 250 is guaranteed enough. Still start light (250 mg/week) but realize that there are 225 lb people who respond great to 250 mg/week and there are 150 lb people who need 500+ mg's/week to really grow. So if you do need that 500 mg/week for cycle #2, at least you'll know that from a fact based on your results from cycle #1.