What I would suggest you do in the meantime

-Watch out for state laws, many states have state-level restrictions on NFA items
-DO NOT get it through a 4473
-Keep your mouth shut about it
-Hold onto the parts needed to restore it back to a non-NFA compliant state in case this happens
-In the meantime you should be okay to bring it to the range and everything

I'm NOT a lawyer and this is not legal advice btw.

The danger with getting it via a 4473 is that if it's an SBR, SBS, or AOW, if when you bought it it was an NFA item, like you buy a model of AR-15 that's an SBR, it was an NFA item when you bought it, so even if you put a brace or a longer barrel on it later it's still an NFA item, and the ATF will know that. What might be okay though is if you buy or transfer something through an FFL that wasn't an NFA item when it was first sold, someone later made it an SBR under the current rule change without registering it, and then sold that to you, that should be okay I think since it it was never on record as an NFA item.