It's hard to tell which trades are retail and which are actually by market makers themselves. However, there are some sites that show which market makers ate typically retail and those that are institutional along with known ones for diluting shares. If you google "retail market makers" you should get a few nice sites.
On the bid and ask.... Bid side are buyers. Ask side is sellers. Picture all of us here on the board in a parking lot bidding for some item we all want. The more of us bidding, the higher the price often will go thus showing good bid support. The more than want something (a stock) the better. On the flip side, the ask side are usually people selling shares so ideally the fewer you have to the upside the better. It's all about supply and demand. The bid side is the demand and the ask side is the supply.
5 million bidding on something and 40 million on the ask, not so good. 40 million bidding and only 5 million on the ask, much better scenario.
