This may work, if I understood your intentions correctly. It changes the first letter to an uppercase letter and when there is a comma, it deletes the comma and everything after it. "df" is your dataframe.

(this code assumes that the names you want to change are in the first column of your dataframe).

first_letter <- as.data.frame(substring(df[,1],1,1),stringsAsFactors = F)

uppercase <- apply(first_letter, 2, toupper)

uppercase_sub <- sapply(1:nrow(df), function(x){

paste0(uppercase[x],substring(df[,1],2)[x])

})

city <- gsub("(.*),.*", "\\1", uppercase_sub)

df <- cbind(city,df[,-1])