As far as cattle, I would try to buy pairs from a local breeder/cattleman that is near enough to check them out before hand. Disposition is more important than hide color in a small herd with lots of people contact.

I would start with maybe just 3-4 older bred cow pairs. also known as 3-fers. Cow/steer if you want some to sell or for the freezer and or Cow/heifer if you are looking to build, or 2 of each.

This way you have cows that know how to have a calf and are bred so you don't need to be messing around with a bull or AI the first summer.

For a perimeter fence around the outside of the cattle area I like an electric wire on standoffs around the inside of a 5-wire barb or energize the middle one of some high  tensile. The hot wire keeps them from pushing on it and provides a place to tap off for cross wires.  Three acres is way to large for paddocks for a few head unless you can divide each down further with cross wires.

Plan out the fences, water access from all paddocks and at least a simple handling/corral area where you can get them in and down to single file and accessible for the vet to back his truck and chute up to for his visits. Get things in place before buying cattle. You can add more head either by retaining heifers or purchasing later after you get things going.

Sounds like fun. Good luck.

Jim at Dawn