Can you ride a moped in portigal at 16 with l plates without passing ure cbt or with L plates?

Yes. If you have passed your test

Anywhere within the western hemisphere so long as you have your license, registration, and proof of insurance. Some countries, (such as Canada), require non-resident insurance cards. Be sure to bring...

on the front or in the back.

L plates can be bought from most petrol stations or car accessory shops. Try Halfords.

the biggest cc engine you can ride on is a 50cc on L plates i would suggest buying something like a aprilia rs50 as this will get you used to a feel of a bike they also go faster than the scooters