I wrote some notes in class but they aren't great. Could you give me some simple notes. like how to find the average velocity/acceleration, or them at a certain time, or whether acceleration is positive or negative.

I need to find the average acceleration from (0 to 12). they line goes parallel to the S axis from 0-10 (on the m/s axis), then goes down to 0 on 12 on the s-axis.

I know this is simple but I'm super confused about a lot of these things. Help