A lot of sites offer great ways to learn and experiment with robots and programming. Google is a great resource - searching for robots or coding and ‘for kids’ will help you find the most current resources, but here is a list of a few places to start.
Start here for a lot of free samples of educational programs made for ‘Hour of Code,’ designed for new learners to experiment with programming for an hour. Sortable by grade level. Code.org is a great resource to find ways to learn.
CodeCombat is a platform for students to learn computer science while playing through a real game.
For a slightly more advanced opportunity, here are some sites that let you experiment with programming for virtual robots. Can be a little complex, but worth it!
If you want a ‘real’ robot, here are a couple good sources of physical robots and kits you can play with, build and program.
LittleBits have fun kits that are a little expensive, but very easy to build and play with.
If you own a Nintendo Switch, the Labo is a fun addition that lets you build and play using cardboard!
A lot of libraries have areas where you can experiment and learn without having to buy the hardware, and there may be a makerspace near you that offers classes and hardware you can use while you're there.
If you want to draw and animate your own robots or cats, here are some fun and free online pixel art and animation tools.