You can specify global settings for strategies by pressing the Global strategy settings... button at the bottom of Edit Studies and Strategies window.
These settings include the number and the generation mode of entry orders in the same direction and the default trade size (number of contracts to buy and sell) which is set up for buy/sell signals displayed on chart. Enabling "Display FloatingPL study with strategies" will automatically add the Floating PL study to the lower subgraph.
Note that global settings are only applied to the current chart, however, you can save them as chart defaults in the Style menu.