What happens if I have a heart murmur? My mom told me that I had a heart murmur when I was a baby, does it mean that I will develop heart problems in the future?

No. Heart murmurs are very common. In fact, 60% of all kids have one at this moment. I tell my patients they aren't "cool" unless they have one. That said, the quality or type of murmur is important. Most likely it was an innocent murmur, and means nothing except rapid blood flow through the heart and mild turbulence. Future heart problems would be more related to your genetics and lifestyle.
Depends. This depends on the murmur.Most murmur "bad" is evident on day one or the first 2-6mo. If I listen to a kid often enough throughout their life I will probably hear one on all of them. Murmur "good" or innocent has little importance beyond giving you something to talk about.It is not related to adult heart disease.
No, . No, not necessarily. It is important to understand what the source of your murmur was and you should ask your mom if she knows why you had a murmur. You could also request your medical records from childhood. A murmur is caused by turbulent blood flow within the heart or aorta, and can be caused by certain heart conditions but can also be perfectly normal. If you no longer have a murmur and you have no symptoms of cardiology, then there is probably nothing more that needs to be done.