average y values bar graph with error bars

I've done an anova and now I want to display my data. I looking at flight initiation distance in squirrels at different levels of human activity. I have three levels of humans activity (L, M, H) and 20ish inputs of flight initiation at each of those levels of activity. I want to create a bar graph of the average flight initiation distance at the levels of activity and I want to add in standard error bars. Any ideas for the code?

Maybe try geom_ribbon?

you can look at this site for an example of what i think you want

http://www.sthda.com/english/wiki/ggplot2-error-bars-quick-start-guide-r-software-and-data-visualization

Thanks! My bar graph kind of messed up the order in which I want the bars (it showed medium, low , high) do you know what I could add to the code to choose the order of the bars?

If the x variable is character the barplot will use alphabetical. If a factor it will use the levels. I suspect you have a factor since high is at the end. You can change the levels. first look at levels(variable) to see the order. Then you can reorder using code like this
dataset$varname <- factor(dataset$varname, levels=c( "low", "medium", "high").

This is my code so far:
ggplot(df.summary, aes(Anthropogenic_Activity, FID_mean)) +
geom_col(fill = "blue", color = "black") +
geom_errorbar(aes(ymin = FID_mean-sd, ymax = FID_mean+sd), width = 0.2)+
df.summary$Anthropogenic_Activity=factor(df.summary$Anthropogenic_Activity,levels=c("L","M","H"))

But I keep getting the error "could not find function "+<-", what do you think the issue is?

Never mind! I realized you meant do that code on it's own before hand. It worked!!! Thanks!

Here is some code i used. The data frame (ANPP_means) has the meanANPP, Year, SE and there is a treatment group as well (so there will be a set of bar charts for each year on one graph, you can delete the fill= if you do not have treatments)
ggplot(ANPP_means, aes(x = Year , y = meanANPP, fill=trt_label)) +
geom_bar(stat = "identity", color = "black", position=position_dodge()) +
geom_errorbar(aes( ymin = meanANPP-SE, ymax = meanANPP+SE), width=.2,
position=position_dodge(.9)) +
theme_bw()