Python is a more general-purpose programming language and R has had somewhat clunky syntax-but many of these things are changing and R is becoming more "professional".
R is very common in bioinformatics and statistical analysis in general and R packages usually perform much better than any Python options for statistical analysis. But in bioinformatics Python is mainly used for sequence analysis because it was frequently designed for that task and can perform many tasks faster and handle large data sets more easily.
If you are a beginner and want to know more about Python and R programming language then do refer the following video tutorials:
You can get a hands-on project by referring to the following Data Science course which will teach you Data Science from scratch to advance.
And if you are more into videos then do check out the following video tutorial which will help you in mastering in the field of Data Science:
If you want a detailed explanation of Data Science then do check out the Data Science tutorial which will help you in understanding Data Science.