R is a very easy programming language. You can learn the syntax of R in 4–5 days. Even a beginner with no prior experience in programming can learn R in just 2 or 3 weeks. R is majorly used for data manipulation and visualization. Therefore, it just requires the knowledge of using appropriate functions. As the major use of R is in statistical analysis, you need not worry about the internal mechanism of the R language, unlike other programming languages.
If you are looking for an online course to learn R programming, check out this R Programming Online Course by Intellipaat.