Easiest Way To Implement Predictive Search On An Intranet Site

Hi all,

In my workplace, we have an intranet website developed internally that we use for CRM.
The data of our clients are shown there (MS SQL server is used as a backend to store data).
The site has a limited search functionality at the moment (it'll try to match the text you type in one of the 3 fields that are indexed -company, staff contact, and director name).

I'm trying to find info about what would be the easiest method to implement a more sophisticated search (ideally that makes use of AI), like the one implemented by Google or Amazon on their website.
It doesn't have to be so sophisticated, anything better than what I described above would do it.
Ideally, the search should be able to guess what you're looking for based on your role, your portfolio of clients, and previous searches.
It would be great if it could understand what you mean (i.e search query 'song la la la' that returns as result 'ATC -All around the world' on youtube.
It would be great to implement vocal search as well.

But again it doesn't have to be that complex. Any info on where to look or which resources are readily available would be greatly appreciated.
Do you know if there are (and what would be the best) search engines/AI libraries/API that is open source and that would fit this purpose? if this is not the right place to ask, on which other website or forum do you think should I ask for?

Thank you in advance