Easy way :
1. Download the installer (.run file)
https://bitnami.com/stack/edx/installer
2. Make it executable.chmod a+x filename.run
3. Run the installer../filename.run
Hard way:
Install using bash script. Why it is hard because it is gonna give many errors, you need to fix them one by one and start installing again and again until it is installed completely.
wget https://raw.githubusercontent.com/edx/configuration/$OPENEDX_RELEASE/util/install/sandbox.sh -O - | bash
You choose the version of Open edX by setting the OPENEDX_RELEASE variable before running the commands. See Open edX Releases for the tags you can use.
https://openedx.atlassian.net/wiki/spaces/DOC/pages/11108700/Open+edX+Releases
Release names like open-release/ginkgo.2, open-release/eucalyptus.3, open-release/ficus.4 etcExample:
wget https://raw.githubusercontent.com/edx/configuration/open-release/ginkgo.2/util/install/sandbox.sh -O - | bash
Helpful url :
https://openedx.atlassian.net/wiki/spaces/OpenOPS/pages/146440579/Native+Open+edX+Ubuntu+16.04+64+bit+Installation
Hardest way:
Install each package separately like these guides are suggesting. Similar guides you can find for centos and fedora.
https://www.iblstudios.com/step-step-guide-install-open-edx-platform-ficus-release/
I would suggest you to install on virtual machine like docker, vagrant or vmware instead of start installing on your system.