Whatever you do; do not touch containers, apparatus, chemicals - anything in the structure. Do not smell any containers. Do not move or open any chemical containers. Do not turn any light switches or electrical power switches on or off.
If you come in contact with a potential meth lab, you should shower thoroughly and wash your clothing - then call your local law enforcement.
Clandestine drug lab removal and decontamination is a dangerous and complicated process that should be handled by trained, certified professionals. Do not attempt to clean up or dispose of a suspected meth lab yourself. Do not attempt to decontaminate a property unless you have been trained on personal protective equipment and industry standard methodologies.