The part before the Plains Village is simple and not really in need of an explanation.

Plains Village

1. Meet Billager and go to Sevillager.
2. Semillager wants fish so you have to go to Dillinger.
3. After getting fish from Dillinger, trade it for a grindstone and give it to Jillager.
4. Follow Billager to his work station and once there, trade 5 Emeralds and 10 Bread.
5. Go to the Savannah Village.

Savannah Village

1. Meet Willager and go to the village well.
2. Demillager gives string (Don't forget to get extra string for the desert village) Lillager needs string for a cauldron, Phillager needs a cauldron to trade for 5 leads, and lastly Samager needs his three pigs back.
3. Get 10 Acacia logs.
4. Go to the Desert Village.

Desert Village

1. Meet McGyllager and help fix the village.
2. Get cacti, replant the sweet berry bushes, shear pumpkins and fill the dispensers, connect the string in the lava trap.
3. Gear up for the Pillager Stronghold and go there.

Pillager Stronghold

Color Combination Purple -> Red -> Green -> Blue

After that it's all on you for the raid. Good luck! :)