I think in the first one, I don't need a comma before "and" cause they are short sentences. In the second however, I'm wondering whether I need the comma before "and" since it is a coordinating conjunction separating two main clauses... What do you say?
1) Yesterday, I went fishing,and John played cards.
2) In 2007, many people worked on the XY-Project, and several people were included in that process.
Thank you! ;)