401k after selling business

[Shalinder S Dang]

I was a sole proprietor of small business which I sold in July of 2020.  I had a Solo 401K for my wife and I.  Can I still contribute to my old solo 401k moving forward now that I no longer own the business.  At the moment I am not working and my wife has a job that doesn't offer a 401k? 

I have several rental properties though not sure if that qualifies.  If I am not able to contribute what are my options to contribute the maximum amount in a tax deferred account?  This year our combined income will be in the zone of $200K.