I want to build a HelpDesk software like Intercom, now what?

I think you should look for the audience first and then solve their problem.

You won't be able to match solutions like Intercom feature for feature without having a huge amount of resources.

Instead maybe try finding a subset of Intercom (or any other similar platform) users that really only use it for one specific feature. Then offer them a better version of that feature without all the bloat.

Hey yourenottheproblem

First steps first!

You will definitly be learning from setting up your landing page and re-iterating its copy. The universe will give you more hint and advice after you prove to be a valuable member of the cast who can be entrusted with further directions for their personal journey of growth...

All the best!

Christian

Edit:

In writing your feature copy you will be finding out more of your (in part) imlplicit ideas and (connected but maybe hidden) concepts, which you probably may not have expressed yet.

After finishing your page, you have something to show to people, you can ask for their feedback with a more tangible asset. Maybe you should do things that don't scale: writing emails, making calls, asking for customers' insights...

Maybe in the process of building the landing page you will have an impulse of distraction; I think, often they are worth being considered and being followed for a while. Some thoughts or even first steps...

(I am being distracted constantly for three weeks after setting goal and plan for the next project. Sometimes a distraction relates to what I have done before, or set up but not finished yet. A next building block years after laying the foundation.)