I'd like to know how to make an actor walk somewhere after you pick a certain dialogue. In this case I hand in an item, then the guard goes "Follow Me".
The guard has to pass through the door into an interior cell, then walk to an npc, and prevent combat from happening. I just have no idea how to make them walk there... :S

It's for the MS09 quest, the guard I want to move is MS09GuardLvl and he has to go inside Northwatch Keep.
There is a script that enables NonCombat though whenever I talk to him ingame, he goes "Follow me", does nothing and the npcs still become hostile.

It's the MS09 quest that comes with the standard game, I tried fixing it cause it's broken when you want to solve it peacefully

Anyone?

Still no one? I've tried looking at scenes, such as the MQ party one where people move to another npc after you finish the dialogue, and Delphine to go to the attic room, but I don't really understand what to do.

you need to make a package that tells him to go to certain markers, but that package would need triggering on the follow me dialog, once there, you would need to make his package change again to continue doing whatever he is meant to do.
If you cannot do this I suggest you look at more tutorials and "experiment" with trial and error to learn more.
GL

Factions may have something to do with this too. might be worth looking into.

Factions? If you mean the imperial legion thing, I have fixed it all except for this part where you only need to follow the guard to rescue the guy. Atm, I have the quest set to alter the rank for the Thalmor faction to 1 to make them neutral.
Thank you for the package thing! I'll place the markers then, hope it works! I thought I had to use scenes.