There is not really such a thing as a normal heart rate, since the heart rate is determined by so many different physical factors. For example, elite athletes often have very slow heartrates, sometimes in the range of 30 or 40 beats per minute. On the other hand, normal, reasonably healthy young adults may have average heart rates of 60 to 80 beats per minute. In addition to fitness level, gender and age also factor in to what might be a normal heart rate for you. Many medications, such as common medications for blood pressure control, will also affect the heart rate.
I would not be concerned by your slow heart rate alone, as it would lead me to think that you are probably more fit than others. However, if you do not exercise regularly and have a very slow heart rate that would be unusual. Also the combination of occasional dizziness
and slow heart rate might be an indication of a problem with your heart rhythm that might need to be investigated, depending on your age and whether you have any other serious medical problems.
I recommend that you get in to see your primary care doctor
for a good checkup!