Also, since you're new to it. Once you have some money in the account, you can BUY instead of transferring money to buy later.
The difference is that transferring money takes 3 days for ACH to clear and then you can buy. If you just click "Buy Vanguard Funds", set your investment (up to your current account balance) and Vanguard fronts you the money and buys the fund at todays price (during market hours). If you ACH fails, they will liquidate the value needed from the fund... not usually a problem if you money/banks are good.