Here are a few tips.
1. Understand that it is a long process.
2. Start training at gym that offers MMA.
3. Refer to number 1
4. Be consistent in your training.
5. Refer to number 1
6. If during the training process you decide not to compete it is OK to keep training for the enjoyment of it. No one expects you to fight. 85% of people that have ever trained at my facility just wanted to train for fun.
7. Refer to number 1
8. Be willing to train at other gyms with different people. You cannot be successful without being open minded in training.
9. Training is expensive. Gym dues, equipment, inevitable injuries, travel, and so on. This is not a cheap endeavor.
10. If you have zero background in combat sports do not allow any coach to put you in a fight in a short time frame. The fastest anyone fought on my fight team was 9 months and he had a world class wrestling background.
11. Do not choose fighting as a way to pay your damn bills!!!!!! That is the most asinine reason to fight.
12. Refer to number 1