How do i create a reminder? + How do I make notes of contact?

How do i create a reminder? + How do I make notes of contact?

Newbie question: how do I create a reminder?

I create a lead
I need to contact them in 6 weeks

How do I create a reminder?

And, let's say I have spoken to a lead
I want to make notes of the communication I've had with the lead
Where do I do this?
Do I put in the notes section??

Thanks


Omar