Any suggestions for first product launch on Product hunt?

I'd say decide on what your goals with the launch are and understand whether you have the resources for it. With our first launch which we prepared really well, it took almost 2 months of my time to figure everything out, prepare the texts and visuals, discuss it with the team - and on the launch day, I spent 15 hours monitoring, posting and answering to comments, and two of my other colleagues spent quite a lot of time on the launch too. It doesn't mean you have to do all that, but when you start preparations, you need to realize whether you'll manage it all on the launch day. Picking a good weekday is important too. Tuesday, Wednesday and Thursday are the most competitive days,so if you are not sure you can stand against the competition really well, it's best to launch on Monday or Friday (weekends work too, but there is much less traffic on the weekend).