Can anyone please explain how to make a responsive web design with amazing features?
I am a small business owner and I need to launch my website ASAP.
But when I contacted a few design agencies regarding web design and development they showed pretty good designs but were extremely out of my budget.
So I decided to design a whole design according to me because I have some good knowledge regarding design.

Hi
Welcom to CC Forum
Have you got Site Designer as a free TRIAL version, this forum is about Site Designer and how to use it to help make websites,
If you havent yet taken the leap of faith then there are plenty of help videos out there that discuss designing websites. YOUTUBE is a good starting point.
I might add that there is a fairly good reason why professional designers/developer people charge what may seem to be high fees, basically one pays for the years of study and experience that these people have. You can download the free trial version which is fully operational, for 2 weeks, if you decide to take the leap of faith USE THOSE two weeks to get to know your way around Site Designer and how to get it to do what you want it to do for you, don't make the mistake that many new users (to Site Designer and or indeed website development make )and think that you will be able to make it in those two weeks

There are plenty of people here on this forum that can,do and are willing to help you through that learning curve.
the two weeks is a good start, but also be prepared for a longer time to master Site Designer (it took me almost a whole year to get to a point where I can build awesome wbsites with this (and I have been a developer/designer for 30 years and am STILL LEARNING