Just drive it as much as possible and make a fix it list.

Any squeaks or odd noises? Most times that is suspension items that may need replacing. At that point you can upgrade to poly bushes or new rubber bits. You want to make sure you feel good that you have a reliable car to drive. All the electrics are working right? Slow wipers, clean and lube the motor and wiper parts. You will also be getting to know your car and how it works. What feels right when you drive and what just does not seem right. If you want sharper handling then you could upgrade to adjustable suspension parts. Want to lower the car a bit to look better? The cones can be swapped to adjustable ones for that. You will need an alignment when done to get the most out of the adjustable parts. Do the brakes inspire confidence? They are NOT new car brakes but should work well. Do NOT upgrade to race pads, they will not get hot enough in daily driving to work well at all.

Inside, how does the seat fit and distance to the steering wheel? There are brackets that will move the seat back for more room. Also a bracket is available to lower the steering wheel. Do the doors seal good to the body. Might be time for new door seals to cut down on wind noise.

Hi all

I just got a new to me Mini. It's a 1994 from Japan. Looking for any recommendations on upgrades that you would start with. thanks 

I would upload pictures but I can't seem to find a way.