What would be a good tortoise for a beginner?

Russian Tortoises, Hermann Totoises and Marginated Tortoises make good beginner torts.
be sure to read up on those species before you decide to purchase.
and welcome to TFO.

Russians! They are very hardy and fairly easy to care for, plus they generally have BIG personalities and will actually often come to you when you come into the room! Many types of torts would rather be left alone but Russians enjoy our company, it seems!~

I think Russians if you want small and Redfoots if you want something bigger.

A lot depends on what sort of area and size of area your going to be able to house this animal in, where you live (how much time can it spend outside), and what your wanting from this animal for instance do you want lots of interaction or just to sit back and observe him?

I live in Southern CA. I got a big yard and alot of time to spend

I've never been to South Ca, but I believe all of the above mentioned species would do just fine in an outdoor enclosure, in your yard.

(make sure it's predator proof)

Might also want to think about a Desert Tortoise then in addition to the rest.

California has lots of great tortoise groups, if I were you, I would find where and when the local one meets. Go and just visit with the folks and get some ideas. The best part is you can most likely get to actually see a variety of tortoises and have help right there, plus have fun doing things with like minded folks.

Payo, I am also in So. Cal. and i belong to the CTTC (California turtle and Tortoise club) Inland Empire Chapter. Cory (Spikethebest) belongs to the CTTC also but a different chapter. We are looking for longterm homes for some of our DT. and the club has quite a few. I have 1 still not spoken for that is a male at about 8 lbs. There are chapters all over So. Cal you can also go to the website http://www.tortoise.org/ and find the chapter nearest you. They not only adopt out DT but other torts also.