If you want to try your hand in custom content creation, there is a tool for that called Sims 4 Studio. It can be found at this website:
sims4studio.com You can also find Creator Studios and forums at that site. I have obtained a lot of my FREE custom content from creator studios there. You can also get tips on custom content creation there.
Also, this topic should probably be moved to CAS custom content, since hairstyles and worn items (Create a Sim) are CAS custom content rather than Build Buy content (items available in build or buy mode).