Read books and blogs and listen to podcasts of experienced apartment investors and join a local multifamily group. 

I would recommend prior to buying s note to get more training or find an experienced partner for your first deal.

My opinion is that you always visit to meet the team, see their systems and see the quality of their build and the neighborhoods their in at least once.

A good realtor knows what is working in their markets and what is not so you should have one on your team as a trusted advisor.Buy and holds are a whole different dynamic, every investor has their own tolerance for what they want in buy and holds... some like cheaper property that have good cash flow today and do not appreciate that much over time and others are willing to accept less cash flow today from more expensive property but theses homes appreciate more over time.

With so many investment avenues in the multifamily space what niche have experienced investors had most sucesss with?

This means they probably have a team behind them.That team likely includes a property manager.

Building a real estate investing team to invest in Clearwater, Tampa FL area.

If you have a licensed contractor-friend ask them to go with you on your first walk through, they are a valuable asset on your team as well.

Would you like to join an active team?

An experienced land use (zoning) attorney can help you figure things out.