[Ima saver]

Jersey, you can't learn everything in one month. Start out with the lower expense vanguard fund and keep learning. These funds (and fidelitys) are no load, meaning no commission, but all funds have expenses. They are taken off the top, so you do not notice them. simple example. Your fund share price goes up 2.00 per share over a year. They take about 6 cents off the top, so the price only goes up $1.94 that year.
They have to make something in order to do this. When you handle billions, cents makes a good profit for them.
But vanguard has the lowest expenses around, usually. I hope that helps. (and I hope I am telling the expense thing right)