Twist of the Wrist 1 and 2 are books and videos anybody who rides a motorcycle (and motorbike) should read. The rule of thumb, if you have no idea what countersteering is, do not get on a large bike. This would be anything bigger than 175 cc in Vietnam.
Starting this year, the new Yamaha Exciter will be 175 cc. The Honda Winner is surely to follow. These meet the A1 license requirements but are still motorcycles. Expect more accidents especially during the turns.
Luckily 2018 rules will force many motorcycles to use ABS.
READ the books.