I have a huge pet peeve. I am not a huge fan of parents screaming at public playgrounds. I appreciate the hullabaloo of little ones having fun but loud parental engagement does nothing for me.
Learning basic playground signs allows you to be in control of the situation, helps you train your little one to constantly have visual contact with you and adds civility to public settings.
Here is a nice chart to get you started. In addition to the signs on this chart you should learn basic signs available in our dictionary & baby sign language kit such as stop or come.