I would start with small-ish, local shops, like flower shops, beauty salons, bakeries, used car places, etc. Places that are probably run by an older individual that doesn't currently do Facebook advertising. Don't ask them for an 'internship', because that implies something formal that would involve them having to do something.

Just go into the shop and ask for the owner, and tell them something like, "Hi, I run a program in which I do Facebook advertising for free for local companies. I help design Facebook advertisements, and then I help post and manage the ads to get them to benefit your business. Would you like to op in to the program? It's my way of contributing to the local community. I live up on xyz road"

If possible, before you visit:

1) Prepare a well made mock up of what you envision the advertisement would look like (use their logo / slogan from their webpage, etc.). You could have this ready to show to the shop owner.

2) Have already self-deployed the ad on Facebook, and have some data on its effectiveness in driving customers to the companies website. In other words, use your own money to have the ad online for ~ 1 week, and see how many click throughs you're able to get, and the $/click. Tell the owner that, in order to help companies in the local area you've already deployed ads for several local business for a couple days. Show them the number of potential customers that have clicked it, and the $ / click.

3) See if you can get any sort of support from a local community board. Doesn't have to be financial, it could be as little as an email response from them saying they like the idea. It will increase your ability to convince shop owners that you're not a scam artists or anything.

As you build up your experience and successes you could start reaching out to larger, non-local companies.

Where you located? If you're in Los Angeles, I'm always on the lookout for rising talent and people that want to be the best. Age has no effect on who I hire. Rather a desire to be the best, learn quickly and implement fast.

Another option would be to complete the Facebook Blueprint certification program and then offer your services on Upwork. There are a lot of people that don't want to pay for an expert but just need someone to help them at a lower price. That is a great opportunity to learn while someone else is paying.

It's really a numbers game. I'd recommend reaching out to 50 companies. If you only have 2% say yes, you've got an internship.

That being said, there are a ton of great training programs online which you will probably learn far more from which are taught by established people. There are many companies where the digital marketing person isn't super savvy.

How have the results been on your ad campaigns? If they are good, you can easily mention your results to get a foot in the door. I'd recommend not looking needy when talking to the business owner. Try to show how much value you are going to bring and it won't take much of an investment on their part. It should look like a no brainer.

Let me know if you'd like to discuss the best way to craft your intro to get a good conversion from these companies. I'd have to learn more to best tailor your approach.

Your approach should be the same as any (younger) person. No discrimination.

Three simple steps outlined in this blog post

Yes I can help you get an internship
http://creativeagencysecrets.com/yes-i-can-help-you-get-an-internship/

1. Learn how to write a formal business letter. Use proper sentences, punctuation and grammar. Capital letters for your name are important if you want to be taken seriously.
2. Do some research first on the business you are approaching. In your letter explain what you would hope to learn from the company and what you think you could contribute to them. Remember an internship is not one-way. So can you teach me? Your letter needs to be a sales pitch for YOU.
3. Read articles from our blog archive about Interns they will help you understand what Creative Agency Secrets teaches its interns.

Hi there! Be sure to check out their website for job openings, reach out to people through LinkedIn who work for the company and invite them to coffee, maybe they know about job postings that aren't on the site or can connect you with HR. Also, I would write I highly enticing email about your experience and how you want to join their company in particular because you believe in the future of their company and send it to Mark Zuckerberg. It doesn't matter how old you are it is about the drive within you. They may be looking for someone who is older and more experienced in the world sense than the marketing side and get a fresh perspective from someone your age. Age is just a number! Let me know if you want to further brainstorm ideas of how you can achieve your dream!