new to ALFA need advice

The 147 is rather blessed from the normal alfa problems, the weak point is definitely the engine. Check so that they have made frequent oil changes, listen for a diesel sound when idle (this is common and is the cam-variator making that sound, and if so it needs to be replaced) also check that they have changed the timing belt INCLUDING tensioner and wheels and also the belt and tensioner and such for the balance axels. If all that is ok, they usually don't give you alot of grief.

/mopar

Put simpel, buy one with at full service record, and adhere to the service schedule in future. As Mopar writes, the cam and balance shaft belt shall be changed as to latest schedule, every 3 years or 80000 km, which ever occurs first.
Check engine oil level frequently and never let it drop to min. level (refill with ½ liter when midway between marks), until your have an idea of how often it needs refilling.
If you are living in a place where rust can be an issue, get it treated right away if never treated and every 2-3 years after.
Erik