Over the years I have done bits of wiring on my various homes and have
some idea of the general principles.

Current home has some pretty poor bodges from previous owner(s)
including the kitchen wiring. Also needs a new consumer unit.

I have taken early retirement and do not anticipate working full time in
future.

How complicated is it to get to a standard where I could do it myself?
What would I need to spend on tools and testgear?

TIA for any advice.