I am from Swaziland I applied for visa at US embassy in my country but it was declined. I made another appointment but I'm scared It will declined as well. I really want to travel legally because I am just an ordinary person who is willing to travel not to stay in countries but a visitor

I think you should just focus on addressing the reason for your previous denial. Prepare strong supporting documents too, like proof of ties to Swaziland (e.g., job, family, assets) to show you plan to return after your visit.

I will advise you to get a lawyer to assist you in applying again