It depends on what kind of program you go into.
I think what I did was pretty common/reflective of many: a program that meets two evenings a week for four hours, and on Saturdays for eight hours. That took me from mid January-mid April for classroom work and a couple rotations. Then I took the state practical exam in May along with the written NREMT exam, and got my certification shortly thereafter.
I'm sure there are other avenues, but this allows you to work a daytime job simultaneously. I paid for everything out of pocket, but oftentimes if you join a volunteer fire department for a little while, they'll pay for you as long as you're going to be helping them out with your certification afterward.
Again, it probably differs by region, but I live in an area where it's pretty common to have volunteer fire departments in smaller towns amidst a few larger towns around the area. A fair amount of the people in the department aren't qualified Firefigher 1 OR as EMTs; they show up at calls to help however they can, they attend monthly meetings and training sessions, and eventually they'll typically find the time to attend one or more of the certification courses later on. That may be harder for you if you live in an area that has larger, full-time, paid departments and not as much of an opportunity for volunteering.
I became a certified EMT before even realizing there were two volunteer fire departments within ten minutes of where I've lived for several years. I realized I liked having the book knowledge I had, and wanted to see if I could cement that knowledge in practice and help out volunteering, so I joined the fire department. I've only been doing it for 9 months or so, but I really enjoy it. Eventually if I find the time, I may try to get licensed as a medic, but I'll be doing that strictly out of pocket without the intention of doing it for a paid career, and only out of the personal interest in the education and experience value.
Hope it helps somewhat, and good luck when you get back.