New owner will not have title until 10 days from today, which lands on a Sunday, so that's Monday the 15th when title will issue.
The law is complicated and although the facts expressed may seem to be all that is relevant, there may be many other important facts to consider. Also, the law is constantly undergoing change, so what may be correct today, may not be accurate tomorrow. Only a full consultation with an attorney experienced or knowledgeable in the specific legal subject matter is likely to result in the optimal course of action. My practice has entailed more than a 30 year span of many real estate, personal property, and bankruptcy issues. Find out more about me at: FloridaPropertyLitigation.com.
if the HOA was the successful bidder at the foreclosure sale, then they will be the new owner 10 days after the sale. Technically, the landlord may still be the owner, but not for long in all probability. The landlord also must start an eviction action against you with the posting of a 3 or 7 day notice, depending, but that process will also probably take longer then that 10 day period before the HOA becomes the new owner. You should contact the HOA to see if you can rent it from them, as this is typically all the HOA wants for now.
You can watch the clerk of courts' website to see when the certificate of title is issued (typically ten days after the sale) and you can check the county property appraiser's website to see when the new owner shows up as the "owner of record." (the property appraiser can take a few weeks, though, so keep that in mind)
Technically, you should pay rent to the former owner through the sale date. Then, pay the new owner from the day after the sale date. In this case, you probably should write the HOA and tell them you plan to be moving out on April 15th and that you would like someone to contact you to make arrangements to turn over the keys and do a walk through.
Remove your items, clean, and take pictures. Turn the keys over to the HOA or mail them in a padded envelope with signature tracking if they don't contact you.
The HOA may want to continue renting the property to you, so you may not have to leave. They should be contacting you soon, but I agree you should monitor the underlying case to see if the Certificate of Title transfers to the new owner, at which time the former owner will lose rights to the property.
There is a statute that protects tenants during a foreclosure. You have rights that may be protected. You should consult a foreclosure attorney. Many attorneys like myself offer a 15 minute consultation.