WELCOME TO TFL!
It's tough to know what you need when we don't know what you've got. Lee kits range from the table top "wack-a-mole" "lee loader" up through those with progressive presses.
First, get a book. Get more than one if you can. Real books, that you can have with you at the loading bench, is my preference.
Lyman for one. Then the ones put out by the bullet makers. Read them, the sections on reloading in general and on your specific cartridge(s).
That should give you a good idea of what you need for a basic set up. Then come back here with specific questions, and we'll probably give you information overload.
The .45-70 is a very versatile round, with rifles of varying strengths ranging from original black powder guns up through modern ones that can take loads dangerous in the old guns.
Today, the rifles and loads are often separated into three groups, from least strongest to strongest. You said lever gun, (one of the new Marlins??) for them, yes crimping is definitely advised.
I've been reloading .45-70 since 1983, Ruger, Marlin, Contender, and some others. Have learned a thing or two, and am happy to share.
Do some reading, learn which questions you need to ask, what applies to your situation, and what doesn't.
You can load good ammo with a bare minimum of tools, and no matter if its a bare minimum or a garage full, there IS a learning curve, but its not terribly steep, just go slow and learn carefully.
There are a lot of reloading "tools" that are not absolutely needed to make ammo, but are very handy and make life easier.
Press
dies
shellholder
Reloading manual
scale
loading block (note, many common ones will not accept .45-70 base down)
case LUBE
calipers
powder funnel
is a good basic set. Lots of things can be added, some worthwhile, some not so much.
Good Luck, and come back with more questions (you WILL have them!
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