to start:
A MAN SHOULD KNOW HIS LIMITS; safety is always FIRST.
First, let me describe the other side of the tools coin.
Several post here gave good advice, do one stage at a time; start with a single stage press. That can be safe, when you know your own limits.
I want to give close, but opposite advice; do one stage at a time, but start with a progressive press.
I learned on the top of the progressive press line, the Dillon 550b. I only did one stage at a time to start. That lasted about a month before I started doing two stages at a time. It was about a week later I went to all four stages at one time.
First stage:
Sizing the case, decapping, and priming was easy and straight-forward. I saw no reason to question anything there. Pulling the die, replacing with a new die, setting up the new die, and then starting again seemed ridiculous.
Second stage:
Single stage presses also meant I had to buy a powder trickler and blocks. I found I hated moving around filled cases of powder. I kept bumping them.
After I put powder in, I immediately wanted to seat a bullet on top and protect.
Stage three:
I immediately started seating bullets; which kept my carefully measured powder, covered and protected.
Stage four:
Of all the stages, Crimping is most problematic; strong, soft, taper, or profile.
It can show the error of the other stages, or mask them, or fix them. I try to never correct other stages's errors at stage four.
Cases that aren't trimmed to length can cause seating errors of too much or too little which are compounded at crimping when not caught in the seating stage. Bullets without defined crimp grooves can cause issues when starting. Too strong of a crimp can cause case bulge just below the mouth.
A progressive press where only one round is produced at a time, is best at showing errors before hundreds of one stage errors can be made before they are discovered. One bad round, I can handle; several hundred and I can start belly-aching big time.
But if there is one recommendation I always make, it is to find a Mentor who can teach. Someone with experience who can show you the ropes and then watch you, can save months or years of frustration and danger.
You may even discover what type of press and accessories you like.
I only got about two hours worth my first time and I am still thankful I went that route.
If you learn through trial and error, then you MUST get a mentor. People learn from reading, others learn from watching, some just have to pizz on that fence themselves to find out. If you are the last type, GET A MENTOR.
Prescut
IMO, Redding is the best and most expensive dies by far. RCBS are excellent dies, price, and customer service. Lee FCD and Lyman "M" are nice specialties.