Is it normal for my first child to move at 18 weeks in my tummy? and i keep feeling cramps! please let me kow?

Yes its fine to feel your baby move then. I felt my son move at 17 weeks. Id mention the cramps to your doctor or midwife next visit. Its probably just you tummy getting bigger to make more room for the baby but mention it anyway to give yourself peace of mind. Good luck. xx