My test results came back with weed and cocaine... I use neither in life. How do I fight it?

Test clean.

Lol I am clean sir... for over 20yrs

Request/demand a verification test, or get a certified test done of your own.

When you do any drug test the company doing the testing should be using the proper chain of custody. If it was a urine test did you sign and get a copy of the chain of custody form? Did you initial the security label that went over the specimen container? This would insure they didn't mix up your specimen with another person. Did they do a GC/MS confirmation test to confirm the presence of the metabolites for THC and cocaine? I would need more info to give you a better idea of what is going on.