You will need all purpose compound mud to get the job done. Buy a 5 gallon of mud, 6 inch knife, and mesh at any home construction store because you will need a lot of it if you are mudding a whole house. Apply some mud on the seam/joint of the drywall with a 6 inch knife. Then use a mesh fiberglass tape and tape it onto the seam of the drywall. Once the mesh is stuck on, slightly scrape the mud off the tape. You do not need to press hard to do this. Make sure the tape does not come off the wall and if does, you are scraping it too hard. Do the same for all the screws on the drywall. Allow the first coating to dry overnight.
On the second day, scrape all the bumps off the drywall with a sand paper. Apply a wider second coat along the seam of the drywall and on the screw. Try to not apply too much coat as you will have more sanding to do. Allow the second coat to dry over night again.
On the third day, repeat the same work.Once you have completed the third coating, use your hand and go along the joint and screw. The coat should be not be too thick to sand and if it is, that mean too much coating was applied. Once all the work is satisfied, you are now ready for sanding.