Somewhat embarrassingly, I do like a bit of summer whittling. It's just very relaxing when sitting around. I've very little creative or craft ability. I just take a bit of wood and see where it takes me.
A good starting point is spoons. I quite like making small spoons for spice jars. They are easy, although you will need some form of gouge or Dremel to help create the bowl. Simple forms like fish are also good to start with.
I like using green wood, so freshly cut when growing. Only a small piece is needed. Sycamore is perfect. It's easy to work with and has a beautifully smooth surface. Birch, apple, pear, olive are pretty good. I don't like oak or beech.
I prefer a small traditional three blade Whittler pattern knife. Main clip blade one end and pen and coping blades the other end. Folding and legal. They look nice, but aren't cheap, although Rough Ryder is a pretty decent affordable Chinese make. Any knife can be used, Swiss Army, Opinel or the type you picture. A larger knife for roughing helps.
Some of my crude offerings (I don't mind members taking the piss - family does!). Also, a couple of Solingen made Whittlers. A beer barrel oak from Boker and olive from Robert Klaas made for an Australian retailer called Angus Barrett.