First welcome to the forum.
Well you can continue reading up on the subject for free on the net. Buying all new is nice but buying used over time as deals appear is how I did it in the dark ages before the internet.
You already have the beast tool going and that is someone who is already a reloader that can act as a mentor. When you find a used press ask if it is a good deal and so on.
I have mentored several and teach a reloading class at our local range. I would ask him if you were to buy dies and consumables like primers, bullets, and propellant if you could use his press at first. Make sure it is when he wants you there if he says yes. Also buy the stuff for your own setup as soon as you can so as not to be the guy "that takes advantage forever". Who knows, when he sees you are really serious he may know of other reloaders that have used equipment they will sell for cheap to get you started also. Reloaders seem to be the best of the best in regards to sharing knowledge and surplus items they have outgrown or upgraded from. Just my 2c.
Now on to needs,
A manual could be online but book has a good reloading section to read and refrence.
A press
Away to weigh your charges (used balance beam)
Dies for caliber
A set of cheap calipers (Harbor Freight $12 on sale)
The above mentioned consumables
A way to prime your brass if not provided with press.
************Other*******useful******stuff******
Chamfer deburr tool
Case trimmer tool(s) Lee set is cheapest
Powder measure to speed up loading.
You can use dippers instead of a scale but that limits you a lot.
There are those that will say get the Lee whack-a-mole kit for cheap and a hammer but for 257 Bob I dont think they ever made one so that is off the plate so to speak. Also a handheld press is cheap but frustrating.
The reloading section at the top of this page is a great resource too. Asking questions when you get stumped is always encouraged as well.
A lot of have started with little and over time made out well.