For me I started out on a few hack n slash style games skyrim & the witcher 3
The witcher 3 is such an immersive game and I have played it again and again a gazillion times, good way to get familiar with your controller also :-) But definitely not a game to be played around children as it full of gratuitous sex & violence the finishing moves in the sword fights are spectacular. If you like the TV series you'll definitely love the game
First time round I would play Fallout 4 it's a shooter with a difference & some of the weapons you can get around believable, the one thing I loved about it is the has a VATS aiming system that allows you to choose what part of the target you want to shoot. It also allows youu to add some mods right from the get go, I cheated on my first couple of playthroughs Some seriously good fun. My first game I also use God mode gear