Congratulations on your 1st blood donation, feels pretty good doesn't it?
Definitely drink lots of fluid before and after donating, and an extra donut doesn't hurt either...
I used to give blood every 56 days at the same location and around the same time of day. There was a group of us who always seemed to show up at the same time and we all became good friends.
I was a young stay at home mother of 4 at the time and always told people that I was willing to subject myself to a bit of pain to have some adult conversation.
I no longer can give blood due to having a dura patch placed in my brain (long story) but I remain friends with many of the people I saw every 56 days for so long.
Congratulations again, that was a very nice thing to do.