How to start DnD ?

I've done a couple of sessions a decade ago as a player and I'd like to organize a campaign.

I have the gist of what the DM does : prepare the campaign, sessions in between sessions, roll and play for NPCs and more or less improvise depending of what the group does.

He also allows rolls and such.

How should I start preparing my own campaign starting from 0 ? I litteraly have 0 knowledge of DnD and don't know.

Is there guides I could follow ? Tutorials ? A friend recommanded me to do it on the 5th edition

Thanks in advance