I started my latest build as a Viking-like warrior. I wanna keep him as realistic as possible so no magic (Shouts are ok). Any advice for equipment/roles I should take? I have all three DLC packs.

Currently, Level 5, I've spoke to the Jarl of Whiterun in the main story and I completed Dustman's Cairn for the companions.

If you want to make the game as realistic as possible. here is what to do-
1 hit kill weapons. Use the fortify restoration glitch to do this.
legendary difficulty.
never improve armour rating.
never put perks into heavy and light armour.
never increase health.
Never increase magic resistance.

You will be killed instantly (most of the time) if an enemy hits you.

On the topic of hardcoe realism, you could also turn off the HUD (by completely lowering opacity), which also means you cannot see your health/stamina/magicka, never look at the 3D map, require a certain amount of food/drink/shelter per day, turn off crosshair, and never fast travel.

That's how I make the game feel as realistic as possible. However I realise you didn't ask for that; you asked for advice on your build and keeping him realistic. I would strongly recommend full Stalhrim armour and weapon set, as it looks badass and fits the Viking theme with the horns on the helm and so on. In RPing terms, drink alcohol aplenty, court fine wenches, aim for all the Thane titles and possibly even live in the snowier parts of Skyrim - for example you could build Heljarchen Hall.