How can I tell if I have sleep apnea? I live alone. Is snoring related to apnea?

Yes. Do you have other signs or symptoms such as, grinding your teeth, day time sleepiness, morning headaches, overweight, greater than a 15" neck, diabetes, lack of concentration, memory problems? If yes, then you should talk to your doctor. Sleep apnea is the #1 cause of hypertension.
Snoring . Snoring may or may not indicate sleep apnea. Statistically 40% men snore but about 1 in 4 have sleep apnea and of course, as is true with all branches of medicine, there are a lot of variables. Chances of having sleep apnea is higher if you have a genetic link, have habit of alcohol, tobacco or drug use, have HTN (especially if uncontrolled on 2+ meds), irregular heart rhythms or CHF or other forms of heart disease or have nervous system issues like stroke, tia, parkinsons, dementia, seizures etc.. Also high chance of having sleep apnea if you have oral crowding or thick neck size. Symtoms assessment and examination establishes a high or low pretest probability. Only confirmed way to make a diagnosis of sleep apnea is to test for it. Both lab based sleep polysomnogram or home sleep study are recommended depending on your clinical scenario and your doctor will be better capable of addressing all these issues. Hope this helps.