to find out why you should not log in as root all the time, do this:
1) log in as root
2) create a directory in your home directory, let's call it testdir: mkdir testdir.
3) now cd into that directory and lets create some files in our test directory, like this: touch file1 file2 file3 file4 file5 file6
4) now we will create some directories in here too: mkdir dir1 dir2 dir3 dir4 foldera folderb
5) now let's imagine we want to delete all of the contents of this directory (a common requirement), hmm, well we can't be arsed to do them all one by one, so lets do them all with a one liner: rm -Rf ./*
6) now let us imagine our typing is not entirely accurate, remember spelling mistakes are vrey comnmon when you spend a long time at the computer. Let's assume you added an extra space by mistake back there (perhaps you brushed the space bar by accident?), try typing this instead: rm -Rf . /*
7) well hot damn, i suppose you notice that you just completely erased your entire system, including any other filesystems that you had mounted at the time, well we live and learn eh? if we had been logged in as a normal user, that last command would simply have generated an error message. This is just one of many examples of why logging in as root is not a good idea.