Professional fighters in the UFC typically wear 4oz (112g) gloves and amateurs tend to wear 6oz(168g) gloves. When compared to the 8-12oz gloves used in professional and amateur boxing this shows you how much less protection there is for the fighters, in both the fighter throwing the punches and the fighter receiving the blows.
If you are planning to take part in an Ultra MMA event there is a specific 8-week training period before the event takes place. During this, you will have 2 or 3 lessons per week which will be based around BJJ, boxing and kickboxing.
Mixed Martial Arts(MMA) is a difficult sport to get into because it involves several different disciplines and to compete professionally you need to be pretty good at them all across the board. You will need to learn Brazilian Jiu-Jitsu, Kickboxing/MuayThai and Boxing.
For many years fight sports debated who was the best. The boxers thought they would beat the karateka that practice karate and the wrestlers thought they were more capable than the kickboxers and the Jiu-Jitsu guys thought they could beat everyone.