Cattle are hard on your ground, so start by thinking about what you are wanting to achieve.
If you just want some meat for the smallholding, and don't have a particular passion for cattle, and don't have unlimited ground, then buying pairs of weaned castrated bullocks might be a good way to go. You may be able to find a local dairy farm that produces half-beef calves (eg Angus x Friesian) that would do. It's certainly a good way to start your journey with cattle, as others have said.
If you prefer the idea of wholly-home-grown, so want to ultimately have cows and produce your own calves, then you need to think in terms of at least 2 cows. (Not only must cattle have company of their own species, but that company must be of their own 'age and stage' too, so one cow with one calf is not kind and is contrary to the Animal Welfare Codes.)
If you are producing meat from your own calves, then you will, at steady state, have 2 cows, 2 yearlings and 2 new calves. If you go for a slow-maturing type, you may want to keep them to 30 months, so that would add another 2 adults to the picture.
Depending on your ground, 2 cows plus their followers will need an absolute minimum of 5 acres (7 if you're keeping to 30 months), and double that if you want to grow your own winter forage. (As opposed to buying it in.)
Winter forage requirements will be of the order of 1/2 small bale hay per adult per day. You're in Surrey, I see, so your winter won't be as long as ours up here in Cumbria, nonetheless you'll probably need to feed hay for 3-4 months. So 4 adults x 100 days x 1/2 small bale = 200 small bales. At £3.50/bale (if you're lucky), £700.
If your ground gets wet it may poach, especially if you are tight on space, so then you would be needing to bring them in for the wettest months. Add straw to the costs.
So buying in bullocks would reduce the load on the ground, and save the overwintering costs of the cows. Around here, we can buy decent Hereford x or Angus x calves for around £200 unweaned (1 month old, still needing milk for a couple of months) or £350 weaned. At 9-10 months old, decent weaned store beasts (usually 3/4 beef or more) are around £600.
Cheaper bullocks would be dairy breeds; Jerseys fetch very little as bullocks, but make wonderful beef, lean dark marbled
. You get less meat on the carcase, of course, and butchery costs will be the same whether it's a fully-muscled Hereford or a lean and lanky Jersey.
Just to throw in a curve ball... I see you are also thinking about milking goats. Have you thought about milking a house cow instead of having goats? Dexters, Shetlands, Jerseys, Red Devons, amongst others, would make cattle who could rear a calf for you and also supply milk for the house. If you have the land and really get into cattle, you could also buy in calves to rear on the spare milk; my Jerseys are capable of rearing their own plus 3 or 4 calves each per lactation, as well as giving milk for the house, the lambs, and anything else that needs it.