main quest is finished? So I can start mods that do start only after the main quest ends ?

It would be faster that you edit the mods so that they begin right away instead of using console commands that will probably break your game. You could also play the main quest entirely...

It's not that simple: finishing the main quest require you to finish all quests before it in a specific order.

Each quest make changes to the world, which stack progressively up to the last quest.

If you want to skip the main quest, you need to replicate all these changes, one by one, from the first to the last quest, else you'll create bad consequences, like:

• actors who are alive but should be dead instead
• actors/item which don't exists but they should have been created instead
• inconsistent dialogues, where people talk about past events
• the oblivion gates are never opened or never closed (based on your current progress), which breaks all other quest which require you close some gate.
• break all other quests (even from mods) which wait for a specific quest to complete, but this quest get skipped instead

There's no such command which can replicate all the quests consequences, but you can create one: you need to accurately study what each quest do to the world and create a script which apply all changes one by one in exactly the same order. A long task, in my opinion...