Hello, I am the individual responsible for providing access to archived material to the general public for our journals, presentations, videos, etc., all of which are in digital formats.

I am looking for a simple method to make these files accessible at low or zero cost for educators, etc. I prefer a method whereby we have some form of automatic authentication or limits on how much or many links any one user can download material.

Suggestions?

if you have no idea how to do this [most probably] you have to pay for it. You need to have storage which is online "forever", a web server (like apache) which again should work continuously and if you want to put it on the net you need to register your server (to have a common name).
Also you need to keep it running, you need to administer/configure it, manage the users, authentication too.
From the other hand you may try to "rent" a web server with some storage space.

I would have a look to nextcloud with a set of directories shared with the default account group.

To run it you need what pan64 said.

For home or external costs :
Hardware, depends on the max load (how many users).
Bandwidth, as hardware.
Domain name, from 12 bucks a year (do not forget to renew).
Certificate, CAcert.org or additional cost.

Pay a cloud storage provider. Seriously.

You would be able to stumble your way through a bunch of tutorials and eventually get something up and running, but you'll be so focussed on getting it to work, you won't be concerned with "is that how its supposed to work" and what steps have I missed that'll make this production worthy, safe and secure.

There is a really good presentation, I forget what it is, and who. All I can remember is the author regrets his choice of title. I'll paraphrase/quote one slide: Getting started with technology is easy. Operating that technology at a professional level in production is very hard.

I'll second the advice above.

I started using Linux because someone told me that I could self-host my personal website with Linux. It was three months before I brought my self-hosted site on line--and I had had a website at members.aol.com for several years, so I was not a newb to websites--and it was several years before I knew what I was doing from a hosting standpoint.

And mine was a personal website that I run as a hobby (though, like many hobbyists, I'm quite serious about it).

You're talking about a business/educational website which contains stuff that matters (whether it contains "web pages" or is just a file repository, it's still a site on the web).

Get it up and working. Then, if you want to look at alternatives, do so at your leisure.

Full Disclosure: I no longer self-host. I now use a hosting provider because I moved to an area where the dominant cable provider is actively hostile to self-hosting, that is, it blocks port 80. My previous hosting provider was passively hostile to self-hosting, in that it did not block port 80 and the wording of its TOS for home users banned "hosting services," but not self-hosting specifically; plus I was such a small fry they never noticed me, so I never had to plead my case.

Read Only access?
That should be simple enough.
1. set up a server
2. Chuck the files in the html root folder and see if they pop up when you open the page in a browser. If not, it's a simple fix of "auto indeces" or some such (depends on how you accomplished 1.)

And yes, I deliberately did not elaborate on 1.
There's a multitude of material on the web and different paths to go and handholding would be detrimental in this case.