LibreOffice is a fun project that welcomes everyone. We provide a series of easy tasks to get working on here: https://wiki.documentfoundation.org/Development/EasyHacks/by_Required_Skill

Since it takes so long to build LibreOffice - we provide easy-to-use VM's with pre-built source trees - so that you can get going ~immediately. See me (purple T-shirt) to get an ssh key with more details here:

https://wiki.documentfoundation.org/Hackfests/VMs/Using_a_VM

A list of some simple tasks that might be fun:

Killing some now un-needed dead code and testing ... as per description in: https://bugs.documentfoundation.org/show_bug.cgi?id=120243

Avoid writing configuration potentially several times during startup: https://bugs.documentfoundation.org/show_bug.cgi?id=92529

Calc: add drop-down on sum button: https://bugs.documentfoundation.org/show_bug.cgi?id=120697