We are not responsible for your insurance. Please make sure that you have an insurance for your whole stay in Ghana which also take you back to your home country in case of continued sickness.
Also you need some vaccinations. The most important is yellow fever. Without this vaccination, you are not able to get a Visa. You have to show your Vaccination Card at the Accra International Airport.
Other useful vaccinations are Hepatitis A/B, Tetanus/Diphtheria/Polio, Typhus, Rabies. These are regards of the Ministry of Foreign Affairs of Germany. Please have a look on the website of your home country Ministry for more information. Also you should talk to a tropical doctor, who is responsible for giving you the vaccination against yellow fever.