You will be in trouble because there is no entry and exit stamps in your passport, you'd better go to Ghana to apply for work visa in person, the physical examination record is also required besies the Alien Work License and Confirmation Letter of Invitation, once you obtain a Z visa and enter China, you can apply for Residence Permit within 30 days after entry at the local Exit & Enter Department of Public Security Bureau. The residence permit can be used as multiple entry visa.