Hi @VivianChang939 Congratulations on publishing your first course a great step has been completed! We recommend creating coupons or using your referral link (info here) to help drive more traffic to your course such as using your website, social media, blog, etc.
This linked article to our Teaching Center includes help on optimizing your course landing page for conversions, launching an e-mail campaign.
About the best time to create your second course, I'll like to refer you to one of the best in this topic here.
Udemy Community Team