Hello, I am new to linux, and I am have some doubts about how to install programs compiling from source. I ´d like to know how I can find if a library needed to run/compile a program is already installed in a system. For programs I use "which";there is a similar command for libraries ? Right now I am using find / -name "name of the library" but usually the output is quite confusing. And how I find the version of the library installed ? Thank you.

If you don't already know the answer to your question, you almost certainly don't want to install from source. Sorry if that sounds cryptic but you haven't said what it is you're trying to install, so it would seem likely it's already available as one of the many thousands of MDK 10 packages. If not, or you have some other good reason for installing stuff outside of the package managed environment, you'd really better understand your system better anyway. For example; not knowing that the libraries needed for building stuff are easily found in the *-devel packages and can be easily searched for and found with the MDK package management tools is indicative that you have not really even begun to explore your MDK system yet and it would be unwise to start making unmanaged installations of tarballed software - even if it turns out to be necessary to do so.