Really good information there justanokie
Small cow calf operations can work well, especially if you have pasture year round so you don't have to feed hay, although some supplements are usually needed to meet 100% of the cow's nutritional needs especially when she's pregnant and while the calf is nursing.
Not a huge fan of AI due to the fact you have to really know your cattle to hit them when they're just right for the process, and the semen from good bulls can be expensive with no guarantee of the cow catching. Bulls can be a pain in the neck, but they do their job well and you don't have to worry about it. Just have the vet preg test in the fall so you're able to can the open cows you don't want to feed through the winter.
One good bull can handle 20 cows, so they do earn their keep.
If the pasture can be irrigated, it makes a lot more feed, and a drip system is pretty cheap especially when the grazing is rotated.
For a small operation, although it's more work, doing custom meat where you feed up to slaughter weight and either sell the animal to an individual or slaughter and sell the meat is usually a good way to make more money per lb. than you get though the sales ring.
These days, selling beef that hasn't been fed antibiotics and injected with hormones for weight gain and is grass finished is a good way to get a premium price for the product.
As to breeds, any of the standards work. I like Herefords for their ease of handling, Simmental or Limousin for big weights. Red Angus and Charolaise are usually fairly easy to handle and have good growth.
Black Angus are dumb, bad tempered, love to ride the fences, a high percentage aren't real good mothers, you end up doing a lot more work to keep them alive and healthy, but the Black Angus association really runs a good marketing campaign so "Angus Beef" appears all over the place even thought the meat is just medium quality.
They are easy to find, lots of them out there for breeding stock, easy to replace, and you benefit from the effective marketing done by the association, but after handling them, they are probably the last breed I would choose to have.
Production breeds are bred for fast weight gain to increase profits, but usually require a lot of vaccinations, hormones are used to maximize weight gain, they're force fed corn they can't metabolize well so it forces fat into the muscle to offset the poor quality of the meat. The quality of the beef suffers, but you can produce a lot of it quickly.
You could choose a heritage breed which people really like in conjunction with novelty, can be finished as grass fed, they are more disease resistant and while many take longer to finish, produce a really high quality beef. They can be hard to find, so breeding stock and replacements can be tricky to buy, but they can offset that with their demeanor and ease of handling and calving.
There are a lot of heritage breeds out there to choose from, Ancient White Park, Red Devons, (the Pilgrims brought these to America), Short Horns, Belted Galloway, Kerry's, Randall, Texas Longhorn, or hundreds of other choices including the breed I raise, Scottish Highland.
Heritage breeds have a lot of benefits from the standard production breeds. Many, aside from excellent beef production, are also good milk cows, some like the Randall are good draft animals.
Small operations can benefit from hitting a niche market of people that want premium beef that has has no need for a lot of vaccinations, hormones or antibiotics, Plus, you can sell breeding stock to people that either have the breed or other small operations with the same goals of premium beef, milk or for draft stock.
Heritage breeds can do well on rougher forage too, many are light grazers, and some like Dexters are very small so you can have more animals/acre.
Most heritage breeds take longer to finish than the endemic black-whiteface. Most don't do well in feedlots, but they're usually easier to handle, better meat, the breeders have a longer productive life so you get more calves/cow, ( for instance, I've had Scotty Cows producing and raising calves when the cows are 20+ years old, most production breeds, the cows are burned out by 10 or 12 years old and have to be replaced), and many have special qualities that the production breeds don't have such as lower cholesterol or less saturated fats so people that have medical issues or allergies can eat the beef you produce where they can't touch the stuff from the stores. Plus, if you finish them out, they've never been exposed to the diseases that exist in feedlots and sales rings.
Those are very positive points for health conscious consumers.
You need to do your homework before making a decision, but it can be a lot of fun and really rewarding having your own cattle herd.