My child can't count / I feel anxious that I should teach letters soon

Reciting "1, 2, 3..." (rote counting) and matching numbers to quantities (cardinality) are different skills. Being able to recite doesn't mean a child can pick out three of something. Start with real objects and "which has more?" With letters too, don't rush—wait for the moment your child shows interest and make it fun. Forcing it can lead to a dislike of letters.