Especially for internationals, it is an advantage to have friendly neighbours who can help you with questions or practical things. You could introduce yourself to your neighbours by inviting them to your house for coffee or tea, or a glass of wine in the evening.
The Dutch like to celebrate each and every birthday, and usually invite friends and family (and sometimes colleges and neighbors) for coffee and cake and drinks. Are you invited? Try to figure out what the intention is. Are you expected to dress up, what would the birthday boy/girl like for a present, can you join a group of people and buy a collective gift?
In the Netherlands it is customary to congratulate both the birthday boy/girl AND also his or her family and other relatives by shaking hands and saying 'Gefeliciteerd' (congratulations).
The Dutch have the fairly unique tradition of bringing a tractatie, a treat, to school or work on birthdays.