Hi Liam, nice to meet you. Welcome to WikiTree :)
As soon as you have volunteered and signed the Honor Code, you will able to begin entering family such as your parents, grand parents, etc.
By all means, please do attach the information needed to verify each fact posted (we call them sources) to each profile you create. It's great that you are aware of sources and their importance in genealogy research.
This Help page explains how to affix a source to a profile: https://www.wikitree.com/wiki/Help:Sources#How_to_Add_Sources_to_Profiles
If you have any questions along the way, don't hesitate to ask.
Cheers from Vermont!