HI I'm new to the game and I would like to know if in the game there's the possibility to have two different builds for the same character (for example opne for PvE and one for PvP) like in other games (for example WoW).
You can respec (at a cost), provided you have all the needed skills unlocked and leveled for both PvE and PvP.
Combine that with appropriate gear sets in your bank and you'll be able to switch to any role you like.
In fact, my main PvP char is exactly setup that way.
She has all skill/weapon/other lines maxed and all possible morphs leveled. I can respec her into anything at any time.
337 skill points here. Can confirm I have enough to have all crafting passives. Most of my class trees. 2 armor trees. 2 weapon trees. Fighters guild passives and mages passives. All from dark brotherhood. 80% from theives guild. About 60% ledgermain.
Very nice since if I wanna go play tank I can just equip a few sets, maybe redo my CP, and boom I'm ready. Same with dps. And occasionally I can even heal but I suck at healing so I don't xD.
If you are looking for a press of the button duel spec, it does not exist. As others have said, Attributes, CP, and Skills can all be reset for gold. Most serious players are going to respec CP between PVP and PVE. Depending on the class, you might not really need to respec the other two if you have enough skill points. The big exception is if you are using skills where one morph favors PVE and one favors PVP. In that case, you are best off just respecing the morphs to save time and money.
Easy. Let me explain. I use my Stam Sorc for pve and sometimes for pvp. I have used skill points in bow, 2h, and dw, as well as everything else. For me, its a matter of changing a few skill points on my bars, and switching gear. Easy.
I take a somewhat different approach. I play three characters that are the same elf - all Bosmer, identical in appearance, same name with minor variations. One is a magplar, one is a magsorc and one is a stamsorc. It is intentional that she feels like the same elf regardless of her manifestation. For what it is worth, she is the same elf we played in both Skyrim and Oblivion. The roots of her basic nature go back even further into Baldur's Gate II and Diablo II.