Yes we all have a dream and we all working towards a common gold to achieve our degree.

This is a compound  sentence and you need a comma before 'and'. There are some punctuation errors, also.

'Gold' is a metal; you want to use 'goal'. You need to put a comma after goal, because the rest of the sentence is an appositive.

Yes, we all have a dream, and we are all working towards a common goal, to achieve our degree.