Start getting all your medical stuff in order NOW. Go to the clinic for EVERYTHING. Go multiple times for things that bother you.
Do you have a family (wife and kids)? If so, start looking for a place to stay now. Determine how much it will take for you to move all of your stuff and have that much saved for that because you won't get any of money for moving until you make it to where you're going and turn in your paperwork to the nearest base.
Start networking with people in the area you're moving to in the same field and at companies hiring for the position. Companies tend to typically put military near the top of the pile of applicants so be ready.
It's never too early to start interviewing for jobs, just let them know how much time you have left and would like their consideration if the desired position is available when that time comes, then contact them every 3-4 months to maintain rapport.
Also, everything is pricier. Groceries, gas, etc.
If you get Disabled Veteran status and move somewhere that has toll roads, apply for DV plates and register them with the toll roads to ride for free. Also apply for homestead exemption when you buy your house to reduce or be exempt from property taxes.
Ask for military discount everywhere you go. Even if the store doesn't practice it, a cashier may give you an employee discount.