Definitely not the Crystal Jellies, the material isn't very safe. I'd stick with silicone for a first anal toy. I like the Bootie plug
personally, but that is more of a "leave in" plug rather than something for playing with.
I would say any of the ones on these searches:
more pluggy than probe-y
more probe-y, not for leaving in
All of those should be small enough for a beginner, and have enough of a base to be safe.
Edit: one of the reasons I dislike the ones you mentioned: the base does not really go in enough before widening, and the base is about the same girth as the rest of the toy. If you lost your grip on those toys, I'd honestly be worried about them slipping in, at least to the point where you'd have only a little sticking out to grab and pull back out!