To clarify you have a macbook but are looking for accessories for your ipad?
If so, there are no mice that work with an iPad. To Apple, the touchscreen is the mouse. You may find a stylus helpful. For simple things there are cheap rubber tipped styli that mimic a finger touch and since they are like a pencil you may be able to use adaptive things on it to make them larger....meaning if grasping something as thin as a pencil is painful those rubber bumpers that make pencils larger should fit on the styli.
There are bluetooth styli out there but they run around 100 and ultimately may or may not be simply a more expensive version of the cheap stylus. apple pencils can work with newer non-pro models, but you may also have issues with the thinness of the pencil.
For keyboards, there are apple keyboards that may or may not work for you. I’d suggest that you go to an apple store and give one a test type to see if it will be comfortable for you.
There are plenty of bluetooth keyboards you can explore if one of them works better for you. Or there are also apps like Dragon Naturally SPeaking (I haven’t looked lately, it should still exist) and the iPad itself also has accessibility features that may allow you to use voice commands. THat would be another reason to go to an APple store and see what features the devices have that can help you.