The link given below will take you to a blog website which is used by a lot of beginners to learn R. https://www.r-bloggers.com/how-to-learn-r-2/
The link below gives you five website where you can learn R for free.
http://swirlstats.com/
I think Khan Academy too provides instructional videos for R package. Plus, there are loads of videos available on YouTube that might help you learn the basics of R.