Its been awhile since I've been in 6th grade myself! Be sure to check if this sounds like how you would write. You can edit what you need to, It's finished but I could be off on some things.
Explanation:
Greetings, I would like to welcome you to the sixth grade. I've enjoyed my time as a sixth grader and I would like to share some of my experiences with you. I learned a lot this year, I recommend you take notes and pay attention often- so you can be better prepared for class. You should also get you're homework in on time. You don't want to get behind in class on work.
There are plenty of good memories I made in this grade. I met some of my closest friends while I was in this class. The projects our teacher also let us do were fun. Being here made it easier for me to prepare for Seventh grade. I hope you have fun this year too.