I started with steel and went to carbon later. I liked my steel bike so would not tell you no to a steel bike. If you want to climb faster, the weight of a carbon bike cannot be beat. It will get you to the top quicker and easier!

If you ride in really windy weather, you will notice that the bike moves around easier and so won't feel as stable there. Can be a bit scary at first.

Most carbon frames do not just fail any more than a steel bike just fails. It is usually caused by something unless it is a weird one of a kind defect in manufacturing. This does not happen that often.

Of course, most steel bikes are cheaper so I would not tell you which way to go