EIN Filing and Solo 401-k

[Farai Simbabure]

Hi BP Gurus,
We own a rental property but don't have an LLC set up, and don't intend to set up one right now. We need to set up a Solo 401-k through vanguard but they need an EIN to open an account. Have the following 2 questions:

Should we proceed and open an EIN through IRS?

Will the EIN create complications when we file taxes because currently we file married filing jointly?

Thanks

Farai