What to look for when investing

Where / what is the best (ideal) real estate investment? Commercial, Mixed use, Multi family?.. The choices can be definitely be daunting when getting started.

1.What return should investors be looking at on the Cash (down payment) investment? 

2.Obviously older buildings and poorer areas hold higher returns; how old is to old? how hood is to hood? 

3. Is it worth sacrificing quality for cash?

4.When getting started what are some concerns to have?

5.How long do you typically plan on holding a buy and hold property?

6.How can you be sure to keep the property occupied at all times?