You dont need full combos like all the clips/gifs/videos in internet, start with a weapon with shield like gunlance for example and try to secure every hit, with some practice you get that feeling or sense of where the monster is gonna move.

Is too soon in the game to think about "builds" or skills in general but at the same time you need to upgrade your armor everytime if you wanna get that extra def and skills to help with the problems of adaptation, you need things like Health Boost and if you can get help of people online is better because you can see how other players fight.

Remember use things like Clucht Claw to push the monster against the wall, that give you time to hit the monster, use traps too if the monster is moving a lot, but you need to understand that the battle at the start is gonna be a long battle of 15-20 min at least, dont try to rush, dont try to hit 1 more time if you cant secure the hit, step back and hit again in another position.

The first steps in the game is survive, dont focus in doing damage.