If you’re interested in making the switch, there are several things you should know. I use the most popular flavor of Linux: Ubuntu (currently 16.04 Xenial Xerus) so my advice will be tailored to that distribution, though there will be some degree of generality among distributions. Interestingly, nowadays it seems all the popular OS have “gone back to” the Linux model of getting programs (i.e. through some kind of repository software). So, you’re probably familiar with using an “App Store” or something of the like to get your programs now, even on a computer. This actually used to be one of my criticisms of the “feel” of using an OS like Ubuntu, but now it’s pretty standard. Anyway, the easiest way to get new programs for Ubuntu is to search in “Ubuntu Software,” which is basically their “App Store” program. If what you’re looking for isn’t in that main repository, you can download *.deb files from websites, which are basically like Windows setup files.
For stuff that’s more focused on my work as an ecologist, I often use R. A curiosity of sorts is that the install messages for packages are often more verbose; I’m not sure why. In any case, be prepared to track down dependencies that are often automatically taken care of for you in Windows.