Orderby custom sorting links?

I am trying to create links and sort the posts by custom fields. How does one do this? I tried WP-Smart-sort and it was great, but the free version didn’t provide me with quite what I was looking for. I bought the pro version, and it won’t run on my server.

So I’d like to custom-code this. It seems as if this should be simple. Can anyone point me in the right direction? I’m no pro at PHP, but I can get by.

Website in question: https://horizonrentals.com/listings/vacation-rentals/

I want to create these links above the posts area:
Sort by Title | Sort by Max. Occupancy | Sort by Bedrooms

All of this would be sorted ascending.

Help?