There's a thing called Media Buying. It's legit - talk to facebook if you have a budget. Also, set up your own Facebook Business manager for Likes campaign that let's you reach out to your desired / specific target audience but with a price to pay to Facebook of course.
If you don't have enough budget for campaigns, go manual mode. Join facebook groups, facebook conversation and promote your Page

And lastly, share it to your personal page and ask your friends to share it and like it as well.