What you need to do is befriend someone who, like me, has more MF cameras than strictly makes sense.
Excluding my old Kodak 616 folder, I had one MF camera for just over 20 years - a Mamiya C330 TLR. Since 2003 or so, I've been buying and trying a number of others - 645 SLRs, 6x7 Rangefinders, another Mamiya TLR body...
The C330 is a good first MF camera. It, like other TLRs is sufficiently different from 35mm SLRs as to encourage a different approach, which is a good thing.
If, on the other hand, you love SLRs, Mamiya 645s in their various versions are good, and the lenses and most accessories are very reasonable.
I've been experimenting recently with Koni-Omega 6x7 rangefinders. They too are quite different, and they provide an affordable entry into 6x7, which just happens to be the largest negative carrier for my enlarger. I wouldn't necessarily suggest that they would be a good first MF camera (they are large, and somewhat quirky) but they help illustrate the wide variety of choices out there.
Your decision should be guided by what works best for you. If possible, try them out before you commit, so you can see how comfortable they are for you to use.
Personally, if I was starting again, I'd experiment with a relatively inexpensive TLR, to see whether I liked working that way. The Rolliecord is a good choice. A Mamiya C220 would also be a good choice, because of low cost, and the ability to use the Mamiya lenses on the more refined C330. If you like it, either buy more Mamiya lenses and bodies and accessories or, if interchangeable lenses aren't as important for you, consider a Rollieflex.
If you don't like the TLR, you can probably sell it for close to what you put into it.
Have fun.
Matt