I would say aside from a few weirdos WASD for movement, Space bar for jumping, and Esc for the menu is the standard for default keybindings.
Action keys on the other hand tend to be all over the place. Personally I prefer to bind them to the arrow keys, because those are nice and far apart so it’s less stress on the shoulders, but that piece of wisdom hasn’t reached the market so far. “M” for mute or the Map. Tab is also commonly used for the Map. Crtl or shift for dash. “F” for “use” or healing potion. Or “H” for healing potions when “F” is already in use. I commonly see “Q” and “E” for stuff you would bind to the R- & L-shoulder buttons. (Maybe they could be used to cycle through equipment?) Alt is awkward to reach for human hands when using WASD. I can’t remember seeing “Enter” being used for anything in the last decade, but that might be due to bad memory or instant rebinding.
So thus, my personal suggestions would be: WASD for movement. Space for jump. Arrow keys for the 4 Abilities (people might like it). Shift for toggling autofire - because why would I want to hold down a button 97% of the time. “F” for some kind of panic key, should you later need it.
Mirroring what 40wattstudio already said: A screenshot or two would be helpful for giving better advice.
Also: There are QWERTZ as well as QWERTY keyboards out there, so making Z/Y a default key for anything is a terrible idea. Have a look to see what other keys differ: Wikipedia.
Other than that… Don’t forget mouse support for the intro and ingame menus. (Especially with the way you described equip/unequip items.)
Lastly I would like to point out that the lack of an option for rebindable/remappable keys or blocking the arrow keys from rebinding had made me refund games in the past. For some reason, there’s still “potential for growth” in that area since the era of flash games ended.
Hope at least part of this helps.