My cat went into labor yesterday had 1 kitten it seems to be fine, and is acting normal.and is acting very normal eating ,drinnkin,and using the litter box

Probably OK:
Is it normal for a cat to only have one kitten

Probably just fine, but keep in mind that if a cat in labor is disturbed she can halt labor for up to about 24 hours until she is comfortable with her situation and surroundings again.
So give her her space and try to resist too much contact with her at this time, just in case.