It's a big topic. Two really quick points:
Location, location, location: important for all types of real estate, but even more so for plazas.
Quality of tenants: Who is leasing the space? Well established recognized chains or Joe No-name operations?
Lots could be said. Network with knowledgeable people, and don't be in any hurry at all to grab the first deal that comes along. Best wishes.
EDIT: Not to prattle on, but I should also add, right up front: Learn how to read, in detail, commercial leases. And learn about the statement of income and expense, and about capitalization rates and what they tell you.