The best place to find answers to your R problems is the internet.
However, finding the most appropriate answer quickly is also a skill and
will improve as your understanding of R grows.
So start with Google. Craft your questions to only have a few key
words that may help refine your search. For example: “select columns in
R” or “select columns in R dplyr” if you want something
tidyverse related.
Many of your Google queries may take you to Stackoverflow. This is a community
full of R users who are asking and answering all things R related. There
is a very good change that your query has already been answered
here.