Hi @lee16
Welcome to the IPFire community.
I am afraid that in the arm hardware page of the wiki
https://www.ipfire.org/docs/hardware/arm#single-board-computers
it says that FriendlyElec NanoPi R5S + others Do not work and are not supported.
I would expect that the R5C is covered by the + others.
It looks like the whole R5 family will not work with IPFire.
There was this thread starting from this post
https://community.ipfire.org/t/arm-sbc-support-discussion/2650/198
which talked about various R5x machines but there was no final conclusion that anyone got anything to work.
Sorry to not be more hopeful for you, unless @spikerguy from that thread above has had any more success in getting any working.