Learn "one penny, two pennies, three pennies".
Get a good Aluminum oxide (two-grades) stone 2" x 6".
Make a solid bed to hold it.
Learn the difference between "dry", "wet with water", and "wet with oil" results.
There's a little bit more to it, but those are the real fundamentals.
Then there is stropping with canvas or leather, rouge, the use of 1200 grade wet-or-dry, and cardboard, but start with the first four - the rest will just sort of grow with you.