Help understanding K1

Every year for the past 3 years we receive a K-1 from an LLC my husband is part of. I am so confused about how to enter since it has both business and rental income.  Turbo Tax recommends I treat them as two separate K1s. Do I fill in all the boxes starting at Box 3 for each one? Specifically Box 20 has a code A and Z. Or where can I learn more about K1 so I wont be so confused next year again? Thanks