Tyler, take the opportunity and get certified!
you dont have to limit your diving to vacations and such, I am sure the is a place for you to dive locally.
The most important thing is your personal comfort.
Instructors cannot teach this.
The more you dive the better your diving skills will be.
I dive year round here in Indiana, rain or shine, and even under the ice.
There is usually a place you can 'refresh' your skills in a pool before big vacations, but I really think people should dive freshwater lakes and quarries more often.
Think of it this way.... if you can tolerate and enjoy the cold water and limited visibility of local freshwater holes while ya perfect your skills then going to prime dive locations with 100+ ft of vis in 78+ degree water is wonderful.
To answer the question- you can get certified and not go diving until your vacation. I have seen many people have a bad time (or no dive time) because they had not been diving regularly.
Its a workout sometimes- getting gear on while a boat is rocking, ocean currents and hard kicking- or the reef cowboys that have to swim a million yards and "see it all" and hes your dive buddy.
Buoyancy is a big issue too. You get a feel for achieving 'neutral buoyancy' and if you dont dive very often this can become one of the most challenging of diving skills.