All the components from theme that can be modified can be found in the ggplot2 theme reference

library(ggplot2)
default <- ggplot(mtcars, aes(wt, mpg)) +
    geom_point() +
    labs(title = "theme plot.title = element_blank()",
         subtitle = "theme plot.subtitle = element_blank()")
default

SDAL Theme

theme_sdal <- function() {
    theme_minimal() +
        theme(
            text = element_text(family = "sans", color = "#22211d"),
            plot.title = element_text(size = 18),
            plot.subtitle = element_text(size = 15),
            plot.caption = element_text(size = 12),
            axis.line = element_blank(),
            axis.text.x = element_blank(),
            axis.text.y = element_blank(),
            axis.ticks = element_blank(),
            axis.title.x = element_blank(),
            axis.title.y = element_blank(),
            panel.grid.major = element_blank(),
            # panel.grid.major = element_line(color = "#ebebe5", size = 0.2),
            panel.grid.minor = element_blank(),
            # panel.grid.minor = element_line(color = "#ebebe5", size = 0.2),
            plot.background = element_rect(fill = "#f5f5f2", color = NA),
            panel.background = element_rect(fill = "#f5f5f2", color = NA),
            legend.background = element_rect(fill = "#f5f5f2", color = NA),
            panel.border = element_blank()
        )
}
default + theme_sdal()