What to expect when getting into MMA?

A little back story: I am far from getting into mma currently. I have way to much body fat for the sport and am broke. On the plus side, I am currently waiting to start a job, so money won't be an issue once that happens, and I am currently dropping bf. I have very basic training in boxing (about month and a half) but enough that I am familiar with how crazy hard conditioning to fight can be. I have also taken a free bjj intro class and have a taste at how difficult and physically demanding even the simplest of grapples and counters can be. I've never been in a fight so I've never been all out punched in the face. My father was a boxer that won the golden gloves and he has told about how many people he knew and saw that quit after their first punch to the face.... TLDR; From your own experience, what can I expect getting into mma? Where should I start? What are the difficulties you have had to face?