For beads I'd go with Flexi Felix. They have a long reputation, are 100% silicone, and are oval shaped for easy insertion.
For a first anal toy I'd go with something other than beads. Beads are more trouble to insert, are often single-shot, and have lots of bumps to catch stuff. I'd start with a finger, small plug, dildo, probe or bead stick.
I have Flexi Felix, and it's a great choice for beginners. First, it's kind of adorable, so it's not something that will be too intimidating. The beads are soft and squishy, so they're fairly comfortable. It's made out of silicone, so it's very safe. Also, the beads increase gradually in size, so you can work your way up to the largest one (which is still fairly small).