Do you have any experience in Digital marketing already? If so, what areas? If not, why are you choosing digital marketing? Are there other topics that you have more knowledge/experience with that you could more easily translate into a side hustle? Rather than spending time learning something completely new, work with what you already know.

Start a podcast for your travel business.

Since you are just starting out, start small and local. Approach local wine shops in your area to see if that is something they would be willing to carry. You'll be able to get a good sense of what the market is like and current competition for shelf space for your product, and how your pricing compares to what's already out there. Once you are in a few different stores, and have gotten some systems in place in terms of selling, shipping and record keeping, you can expand your market. You can do this yourself, hire salespeople or work with a distributor. In my experience, distributors are more willing to work with you if they see you're already in stores and that there is a demand for your product. Another thing to consider is, will you be able to meet production demands if for instance you signed on with a corporate deal which would require x amount of units per order? Growing is great, but growing too fast can lead to other problems.

I agree with those who have suggested starting a Patreon since you already have a large network. In addition to that, however, I would suggest seeking out sponsorships with companies who have complimentary missions and values as your podcast, or products that can serve your listeners. Since you're a social enterprise, there may be grants out there too that would fund the kind of work you are doing. If I knew more about your show, I could suggest some examples of potential sponsors I would approach. I'd also be interested in listening to your show as well! :)

Zoom has the option to record the audio of conversations. Soundcast is another option, which will record individual speakers on separate tracks. The podcasting app, Anchor, will also allow you receive voice messages from people. People can also leave you a voicemail via Google Voice. If you'd like to learn more about any of these options, feel free to call me and I can even test them out with you to see what would work best for your needs.

If I'm understanding your question correctly, it sounds like you want to bypass using a payment merchant like Paypal or even Etsy, Shopify, etc? If you want to make money, you will need a way to collect the money from people, unless you will be doing a cash transaction in person. You can use venmo or Square to accept online payments without setting up an online store. You can try apps like Depop.

You can share the individual song by grabbing the Embed code in Spotify. To do this, find the song in Spotify and click on the ellipsis, aka the three dots (...) to display more options. Select Share --> Copy Embed Code and place this code where you want the song to display on your website. You will also see other options available. If you choose "Song Link" it will open the song in Spotify. Another option is to create a playlist of the songs you want to suggest and embed the entire playlist. If you aren't restricted to using Spotify, you can also embed songs from YouTube or create a YouTube playlist of the songs you want to share. Hope this helps!

You can setup your sales team with Saleforce, which integrates with Google Adwords.

You can use a QR code to print on business cards. There are a ton of sites that allow you to create codes. You can google to see which ones offer the services you need (expires after download, etc)