I assume these are Full Length sizing dies and are for the correct calibre you are sizing. Have you read and re read how to set the sizing die up?
Sizing Die is the one with the decapping pin sticking out of the bottom.
Put the shell holder on the ram and raise it all the way up (pull lever down)
Next screw the die in until it touches the shellholder, then lower the ram and screw the die in another 1/2 to full turn. Set the lock ring, this is where the FL sizing die needs to be. Now put a lubed case in and run it all the way into the die (die should tightly bottom out on shellholder). Lube should be on the body of the case but not the outside neck/shoulder. You can put a dab inside the neck if you want. It should take a bit of force to size the case, but not a ton. I did not like the Lee lube (many people do tho) and I prefer Imperial Sizing die wax from Redding, RCBS case lube 2 on a lube pad or Amsoil motor oil (oil can mess up primers if not cleaned well).
After cases are sized check with a calipre to make sure they are not longer than the max case length in the manual for your calipre. If they are long, trim and chamfer them.
Normally you now seat primers and charge with powder. I think you should wait and aim to make one or two perfect dummy rounds first.
Remove the sizing die and place a sized trimmed case in the shellholder and raise the ram all the way. Screw the sizing die in until you feel it touch the case (this is the crimping part inside the die) now back the die out about 1 full turn (you're not gonna learn to crimp right now) so it doesnt crimp. Back out the seating stem a bit on top of the die. From here you can seat bullets you will play with the seating depth via the bolt/rod on top of the die. I usually only seat the first one a little bit at a time (don't pull lever all the way) to see if I have the stem backed out enough. You can always seat the bullet deeper, but if you start too deep it's hard to pull it out without a puller or kinetic bullet pulling hammer.