I've taken 101 from Mountain View (40 min. south of SF) to Anaheim several times. It crosses rolling hills and passes along the coast periodically once you hit San Luis Obisbo. It's not hard on a car. If your car can make it over the grapevine on I5, it should be able to handle 101. The speed limit is 55 much of the way (rarely less). The drive is much prettier than I5, but it adds a couple of hours to the trip. Highway 1 gets very curvey and can add at least 2 more hours to the trip. Its quite lovely.
When I drive, I like to take 2 days going one way taking 101 and/or, on rare occasions, taking Hwy 1. I will often stop at a beach for a couple of hours (I like the one in Carpenteria; it's considered one of the safest beaches on the west coast) and perhaps visit or stay overnight in Solvang. With small kids, the zoo in Santa Barbara makes a nice break, or Hearst Castle with older kids. But I always take I5 the other way. It's much faster.
There are a handful of rest stops along I5. If you want a sit down meal, there aren't a lot of options. Harris Ranch is a popular stop around half way between SF and LA. It's worth a stop to visit the gift shop and take a potty break even if you prefer brown-bagging it. Another popular stop for travellers is Split Pea Andersons. (I never tire of the Pea Soup) There's one in Santa Nella, just north of Los Banos, just off I5. There's also one in Buellton, next to highway 101, 1/2 way between Santa Maria and Santa Barbara. Since both Andersons and Harris Ranch cater to the travelers, they are advertised along the route and hard to miss. Watch your gas if you are going down 5. There's almost nothing except Harris Ranch between Los Banos/Santa Nella and a place called Lost Hills. Get gassed up before Hwy 152 (Los Banos) if you are worried that you won't make it 125 miles to Lost Hills. There are many more towns and options along 101, although I avoid Santa Barbara. Very pricey gas.
Regardless of how you go, bring your patience once you near LA.
Have fun!