Welcome to offshore fishing! Can you post a map of the lake? I would start by drawing a map of the lake and noting any bends in the original creek channel. In shallow lakes, any abrupt change, especially if cover is also present, can be a fish magnet. Not all points, flats, and weed beds are equal, and a map can be useful. Even if old topo maps aren't 100% accurate anymore, they still provide a guide to finding fish holding structure.
As for the "globs", depending upon your unit and how sensitive you have it set, they could be baitfish, crappie schools, detached vegetation, etc.. A picture and knowing your settings can be helpful. Also, in shallow water, your unit isn't going to be casting a very wide cone, so relying on it to ID fish is very difficult. I fish shallow rivers and lakes mostly in my kayak and I typically use my electronics to track depth, weedline, and bottom composition. The upside is that while it may not actually spot fish, it will give you the information necessary to find places LIKELY to hold fish.