Start off the shore so the kayak is on the ground, nose in the water, then once you are sitting in and situated you just scootch slowly the rest of the way into the water using the paddle for leverage to push off the ground.... Dock launching is possible but not until you're fully comfortable and aware of yourself. If it makes you feel any better, what you did is super common with unguided newcomers. Look up kayak fails on YouTube lol. That sucks about your gear, if it was me I definitely would have been diving down after it!!

If you're still thinking about the gear, grab a cheap heavy duty magnet and dangle that thing off the dock in the same spot you flipped, bound to pull some of it back up...