No, you are not too young. The money you put in today will yield the most results by the time you retire. It has 45 or more years to grow, so it will matter more.
To answer the “what type” question, I need to know your current tax bracket. Almos always, you will be better off with a Roth, but there are exceptions.
If you have the time, you can manage it yourself. But do you have the time or the inclination or the knowledge.
One nice alternative to managing it yourself are Vanguard funds – they have funds with very low management fees, and some indexed funds with infinitessimally low management fees.
-rsr-
Former Certified Financial Planner