I am 2.5 years into my 5 year commercial lease in Louisiana and my landlord has sold the property.
Can I get out of my old lease?

No. When a property is sold any outstanding leases remain in force.

However, the new landlord might be interested in letting you out of the lease or allowing a buyout. So talk to them.

If there was a foreclosure by the bank the lease would likely be void. However, in a straight sale the lease survives. You as a tenant were a selling point to the new buyer, they need tenants to survive. Why do you want/need to get out?