Should I start now, or wait?

I have an idea for a relatively big Minecraft overhaul mod [fundamental changes to crafting, player inventory, mobs. It's a lot. Going to be releasing in bite-sized phases]. I know I'm going to want my mod to be 1.14 focused, since Forge is on 1.14 already, but I see that only the MCreator snapshot is 1.14 friendly. Should I wait for MCreator's full 1.14 release, or start my mod in 1.12 and convert it later? I ask because I don't know how many things could potentially break when changing the version. I'm new to modding [literally have never coded a thing in Java in my life, and barely at all in any other language] and would rather not start something I know will break later and have to be redone anyway.

Thanks in advance.