I am trying to learn how this vacuum press works but instead of plastic I would like to know if any one has some info on pressing sheetmetal.
There are many forming processes for sheet metal.
If you are looking at forming shapes similar to thermal forming, it will take lots of tonnage. Do a web search for hydroforming, bag press and rubber block forming. These processes create enough pressure to turn 60-70 durometer rubber into a membrane state and flow the sheet material around the die.
Learn cause and effect through experience. Mastering those relationships is the "Common Sense" ability within the art of any trade.