Obviously, you should collect what you enjoy most. That said, many people collect blocks with the plate number attached. These are called plate blocks. You may find it easier to buy and sell plate blocks than random blocks of four. Look up examples of plate blocks to get a feel for the format. Also, I have found it confusing to figure out how many stamps in what orientation collectors consider the official plate block. Some catalogs will list the variously traded pate block orientations.
As a new collector, I might warn you about your approach. The USPS has tended in recent years to make a lot of issues in a way that blocks of new issues can get expensive quickly.
Another good way to get a good US collection started is to grab one of those large lots on
ebay. I know that there are lots of folks who trade on this site. And once I get my 50 posts behind me, I'll be happy to send you some starter US stamps if you head that way.
Best,
Ken