Or what location?

Well you get a laser musket pretty early in the main story quests.

Got it but i want more energy weapons

You get a free weapon for joining the Brotherhood of Steel.

It's not like NV or 3. So far, the only groups that I've encountered using laser weapons are synths and the Gunners. Head south from Abernathy's farm and you'll see this little shack with an elevator going up too the highway above. The gunners I encountered there were using laser weapons (pistols and one had a rifle). You can encounter a good group of synths in Fort Hagen. I'll warn you though, there isn't much space, so bring plenty of food/stim's and lots of ammo.

Synths looks like they start to appear at level 8 or 9?

Also met a couple of super mutants which have laser weapons.