I think january as a deadline is an overkill. if you follow the blogdown book, it'll take less than 20 minutes to get things up and running.
You should be already familiar with markdown, rstudio and github, so there's not much else to learn.
As for advice, after your site is up and running, you can keep improving your site by tinkering the hugo templates, learning some html, css or even javascript.
and when you have issues, check yihui's book first, then hugo's documents.