Likely what you're really asking is how to do effective lead generation.

Where "effective" means locating new clients at near zero cost who can pay you $1000s every month, week, day or hour.

Simple solution.

Get in front of groups of people with money.

Simple way to do this. Join https://Meetup.com + attend many business + networking events.

Watch + Learn how speakers, group organizers, attendees all "work the room".

Attend a few of these groups + you'll be generating more leads each week than you can process in months or years.

At the beginning you need to understand your clients, then,
increase their gain, reduce their pain. this is the definition of value and this is how you can make money.

1. Offer training/consulting/advising to companies for a fee.

2. Offer training/consulting/advising to companies, and get paid a % of the results.

3. Offer to generate leads for them and get paid per lead.

Helping others in nonprofit settings is always an option, though making money at high and sustainable levels is not always a certainty, especially when you're first starting out. It depends on the nonprofit model you're working with and the type of service provided.