Like able to strum and sing along without a pause.
I tried to learn guitar and seems like alot of people think it’s easy. But i have difficulties playing while singing. 
Is this normal? What should i do to improve? What are the basics a beginner should learn before jumping to the advance of singing and strumming together?
It’s just a matter of practice. You have to learn the chords well enough that you make them and change them automatically while you’re singing. This is why you start with very simple (stupid) 2-chord songs like Skip to my Lou and Ten Little Indians.
Also it’s easier in keys like A or D, so you don’t have to struggle with the dreaded F chord. F isn’t really hard, but it takes some concentration.
Just keep plugging away, you’ll get it. It’s not as hard as it might seem at first, so don’t get discouraged.