There’s plenty of shortcut keys for what you want to do. I thought you were asking to dissolve from camera to camera inside a multicam clip. Your angles can be toggled with the number keys at the top of your keyboards. A cross dissolve is the default transition in PPro and assigned to Command D. You can set its duration in Preferences. You can select any transition effect and set it as the default.
So if I was doing what you’re doing I would cut the clip (command K) select the second part (D) change the angle (2) and add a dissolve (command D).