Yay! So excited for you!
I'm excited too that this is my area of expertise
. I've been raising sheep for 12 years and actively running a sheep operation for 5. If you are interested in dairy sheep please write off a grass only situation with small acerage. Milk requires a lot of nutrients (if you've had children and nursed then you understand the toll it takes on your body and how much food you needed) and there just isn't enough in a couple half acre pastures to support a productive dairy, that is unless you have one or two sheep only and don't expect a long milking season.
If you are interested in wool and meat the shetland, finn or icelandic sheep are all great choices-gotland and navajo-churro sheep would also be great but are harder to acquire. All the above breeds have a dual purpose to them and are heritage/homestead breeds. None have been commercialized and all are specialized for homestead purposes with a 'mini' size and great personalities to match. They provide enough meat for a family freezer and are relatively easy to handle (of course all sheep have differences in personality). They also provide a double coated wool that is marketable to hand spinners. Because they are more of a homestead breed they have high(er) lambing percentages and lamb easier than other breeds. Sorry to the person who suggested Jacobs my experience has been that they are pretty flighty (though this is just my experience don't write them off based on that).
Now, if you are not interested in wool at all (trust me wool can be a hassle if you don't have plans for it) go for a docile meat breed like the Katahdin. Soays, Barbados, Dorsets and the like are big and a little wild. You can't get many katahdins if you don't have much room but you could have a mini flock of say 1 ram and 2 ewes plus any lambs on grass alone. General guidelines are 5 sheep to an acre with some supplementation.
As far as sheep go you will want to stay away from any of the larger breeds: Romenys, Columbia, Wensleydales, Merinos, Suffolk, Hampshires...etc to keep your farm more sustainable. I raise Romneys and love them to pieces they have a really good temperment and great quality fleeces as well as delicious meat BUT they are quite large. We manage 2 rams and 8 ewes full time plus lambs feb-sep on 10 acres and they do just fine on a pastured diet.
Don't have much experience with goats so I'll keep out of that discussion
Hope this is helpful
edited to add Navajo-Churro