Can accessing root harm my system?
In some cases, yes. Unless you're absolutely sure you need to access root for everything in a particular terminal session, it's often better to just type sudo followed by a command, if you want to access root for that particular command. For example, typing sudo apt install vlc in any Debian-based version of Linux would tell the operating system to access root just to run the APT package manager to install VLC.
One very important caveat to running sudo -i or any other variant we've discussed earlier as opposed to typing sudo before each command you want to run as root is that the former does not log your command history into "/var/log/auth.log". If you mess up, you can't go back and check on what you did so that you can correct it. You'll have to operate out of memory, as root sessions are not recorded.