Fonts from the package extrafont

library(tidyverse)
library(extrafont)
library(patchwork)

family_function <- function(){
  mylist <- list()
  fonts <- extrafont::fonts()
  # loop
  for(i in 1:length(fonts)){
  d <- ggplot(head(mtcars), aes(mpg, hp))+
  geom_point()+
  theme_minimal()+
  theme(title = element_text(family = fonts[i], size = 10))+
  labs(title = paste0("This title has the font family:\n",fonts[i]),
       caption = c(i))    
  names <- paste0("item_", i)
  mylist[[names]] <- d
  }
  return(mylist)
}

d <- family_function()

wrap_plots(d, ncol = 3)