Discounted First Month Memberships

Hi,
I’m looking to offer some memberships with a discount on the first month to really promote the membership option as most of my clients currently attend on packages or one off bookings. I can’t seem to find an option for discounts when creating a membership option. If i create a new membership at the reduced rate, is it easy enough to increase the cost of the membership manually after that first month once it’s already applied to a member?

Cheers,
Belinda