If a snake or chigger is within a mile of where I am, they find me. That's why I advise to save the visits to rural, overgrown cemeteries for cold weather months. But, if you are determined to visit a cemetery, overgrown of not, use common sense and go prepared.
If you have never visited this cemetery, check your directions. Are they exact? So many older cemetery books have directions such as "3 miles past John Smith's farm in a grove of trees in the field." This is ok, providing John Smith still lives there and the grove of trees hasn't been cut. Check out the directions. Often county maps will have cemeteries marked.
Is the cemetery on private property? If so, you need to get permission to cross the property. You don't want to meet an angry property owner holding a shotgun. Get permission and avoid a potential problem.
Never go alone. Take a friend with you. If one of you rolls down a steep hill, twists and ankle or gets stung by a horde of angry bees, the other person can call for help.
Take a cell phone. No longer a luxury, a cell phone is a necessity and make sure the battery is charged.
Take a tool bag. Take just what you need, but watch the weight. That bag is going to get heavier the farther you walk. Include the following items:
Use nothing with chemicals on the tombstones so leave the Formula 409 at home. Brushes with stiff or wire bristles can also damage tombstones, but an old, soft toothbrush can be used to very gently brush away debris from lettering. A spritz of plain water will often enable inscriptions to be read. If in doubt about what to use on a tombstone, don't use it.
Try photographing the tombstone from several angles to get the best view. Sometimes holding a sheet of aluminum foil to the side of the tombstone to capture the sun will enable the inscription to be more legible.
Above all, have fun and stay safe.