Goats need very basic shelter. They need a place to get out of the rain/snow/moisture of any kind because they can't stand it. They need to be able to get away from strong winds. If the mother is pregnant she'll need a safe, soft, clean dry place out of the weather to kid. A three sided structure will be fine if you have constant decent weather. (CA has that stereotype).
Dogigloo's are impossible for you to get into to help her give birth etc, although they are great for non-pregnant females, wethers (castrated males) etc for temporary shelter. They would rather live together, sleep together etc. If you could build a 3 sided barn you might be better off, provided you can make it deep enough that they can get far out of the weather if/when needed. If you were in say, Minnesota you would need a full structure for them to keep out drafts etc.
You'll need fresh, clean water available 24/7 and browse or hay (not alfalfa unless you are eating or milking them). You'll also need concentrate aka goat chow. Feed them small amounts of the goat chow once a day, and free choice hay if they don't have any browse to graze on. The hay can be timothy, orchard grass, or bermuda. Goats are picky eaters despite what folks say, but they don't need expensive alfalfa unless you live next to an alfalfa field, are raising meat goats or milkers. If they are just pets, then any hay is just fine to keep them healthy and in good body condition. You really only need something as expensive as alfalfa if the fat content of the meat on butcher is important, or the taste/fat content of the milk is important.
Laney