After i cast on and i knit the first row i cant seem to get it tight and everything is loose. Can you tell me what i could be doing wrong in the beginning

Welcome! We need more info. What are you making? Can you give us the pattern name and a link if possible? What yarn are you using and what size needles? Are you a new knitter?

Without knowing more you may be using the wrong needle size for the yarn. Try going down a needle size or two. If you’re a new knitter it may just be you need practice.