Pakistan is very good in T20 but not same good in tests and ODI. On the other hand Bangladesh must be looking for some wins against Pakistan to overcome there bad performance in T20 WC. Bangladesh has never won a test match against Pakistan, so Pakistan need to be careful to maintain that record. Bangladesh holds a record of 3-0 in ODI series against Pakistan in 2015.
Pakistan is a far better team than Bangladesh. They will easily win the series the T20 series. About the test series after the recent win in the T20 world cup, the team will be full of confidence and I am sure they will try to win the test series too but in the past, they have played very badly the test format. So it is a dice situation but we will be enjoying some good cricket.
Bangladesh is better at one-day internationals than t20 or test cricket. But Bangladesh is going through a really bad form right now and that will obviously affect their performance. And with all the politics going on in the Bangladesh cricket board and the players having problems with the board and the coaches, there might be a lot of problems that will reflect on their performance.