Can I create a form in Hubspot like, When a person sees a button Example[Download Now] and he clicks on it and form pops out asking his Name and Contact details?
or
[2 step for]
When he clicks the button First step of the form show name once he fills the second step shows email id and Download.
Do you need the button clicks to be tracked? overwriting a Hubspot cta's href to turn it from a link to a javascript trigger is complicated. I'm not even sure it is possible but it is something I have been trying to find the time to look at by request.
if you don't need to track it then your question isn't a Hubspot question, it's a web dev question and is fairly simple if you know a little javascript.