You are seeking a provider of a service.

There is a P2P matketplace where you can submit a listing

Here's a FAQ for that:

There is also a microtask site, https://Microlancer.io which works very similar to something like Upwork.
You can list your service need, and "taskers" (workers) will submit their offers to perform that service for you.

Microlancer also has a "Microlancer Services" mode, which is similar to how Fiverr works. Perhaps there is a listing by a Spanish tutor there already. Probably not, as microlancer is significantly underutilized, but it is possible such a service offering already exists.

But there certainly is someone in a Spanish speaking country today who also speaks English who would love to be your language tutor. That I am certain.

As far as a SN marketplace, would love to see that as well!!!