Also, meetups are mainly good for random socialization and free beer. Sometimes networking, but often only incidentally. You need to get way more targeted than "tech people in my area who also want socialization and free beer." Scrounging at meetups is the last resort of people who don't know who their customer is yet.
Being able to find your customer is one of the first things you have to learn about them. And to start out, go about it like you would trying to find any other thing - just, be a lot more determined and creative about it than you would trying to find a local pizza joint to order from.
Say you want to land a heritage language school as a client. Where can you find these people? Where can you find their clients - who might be happy to talk to you at length about which schools in the area are best for people who are concerned about heritage language education?
* Get on Google, Google Maps, Yelp and search for heritage language schools my_city.
* Check forums and trade publications relevant to heritage language schools. If you don't know them, find out while you're learning the other stuff.
* Track down bloggers who write about heritage language education, see if they mention any specific schools / issues, research those. Connect with any users you find in e.g. comments, guest bloggers, etc.
* Guess that many people who are customers of heritage language schools are second or third generation immigrants. Where else can you find these people? Are there churches, community centers, or local shopping resources that also target them?
Find your customers - by way of their customers or competitors if necessary. All of the above probably have something useful to teach you about making your business succeed.