Hand out the worksheets and then demonstrate the activity with an enlarged copy.
Have the students fill in the blanks on the round one question. On the simple past sheet the question is 'What sport did you play last week?' Then they fill in their answer 'I played ~'.
After that they interview three people and record their answers. Finally pick one of those interviewed and write a sentence about them. For example 'Taro played soccer last week' and show that sentence to the teacher or ALT. They get their sheet stamped then sit down. We start a 30 second countdown after the first one or two students gets a stamp.
After that move onto round two. On the simple past sheet I think its 'Who did you talk to yesterday?' and then round three 'What TV show did you watch last weekend?' Before starting each round make sure all the students are sitting and listening. You can use this time to do some pronunciation practice and add rules such as not talking to the same people as the previous round.
It is also good to have the JTE mention the main point is practicing English and not just filling in the worksheets quickly. Some will still cheat and do that but if reminded more students will do it honestly.
This is a very basic activity and works well as a warm up.