ggplot2 might be a good choice if you are new to R: the basic syntax is applicable to many different types of plots.
Here's your e.g. of a simple forest plot with geom_pointrange. The only trick is that ggplot line plots normally place labels on the x axis and quantitative data on the y axis; this can be changed with the "coord_flip" function, and then by reversing the order of the labels before creating the plot:
label <- paste0("X", 1:6)
mean <- c(1.29,0.76,2.43,1.68,1.22,1.7)
lower <- c(0.84,0.50,1.58,1.1,0.8,1.11)
upper <- c(1.95,1.16,3.67,2.54,1.85,2.56)
df <- data.frame(label, mean, lower, upper)
# reverses the factor level ordering for labels after coord_flip()
df$label <- factor(df$label, levels=rev(df$label))
library(ggplot2)
fp <- ggplot(data=df, aes(x=label, y=mean, ymin=lower, ymax=upper)) +
geom_pointrange() +
geom_hline(yintercept=1, lty=2) + # add a dotted line at x=1 after flip
coord_flip() + # flip coordinates (puts labels on y axis)
xlab("Label") + ylab("Mean (95% CI)") +
theme_bw() # use a white background
print(fp)
