Clips are those “cages” some people use. Clipless is the name given for pedals that use a cleat to clip into the pedal. The latter is far safer. Using a flat pedal without any attachment to your shoe might seem safer, but you face the possibility of your foot slipping off, and you lose any benefit to the upstroke when you’re pedaling. I suggest you practice on some soft terrain (grass) and get back into the clipless pedal scene.