from personal experience-
Gearbox indicator fully lit up, as mentioned above, is a limp home mode. A full fluid and filter change quite often resolved many gearbox problems Ive encountered across 4 different cars. But pulling the codes is a must. it's actually pretty simple- i made my own diagnostic cable, based on the info in the service 'manual'.
likewise, understanding the state of the engine codes, which you will do at the same time.
My cars are all UK models; On european cars, do you have a facility to blink the codes directly on the dash instruments?
Brakes.
The UFO disks and pads will likely set you back a similar amount as buying the car. The standard discs are nearly unique, and no direct fit alternatives exist.
You'll enjoy it, from tinkering to driving
