Yes, you're probably best off with Vanguard. They are very well known for their low fees in comparison to other companies, and fees are extremely important to your returns over time!

If you put your money into an ETF, there won't be a minimum, and probably slightly lower fees than mutual fund. There are two main differences; a mutual fund updates its price once a day whereas an ETF is constant. You can therefore buy and sell ETFs all day along, unlike a mutual fund. You can also buy fractional shares in a mutual fund. The second point is especially useful for people who might (for example) set up a daily $100 to go from their bank account into an investment.

If I were you, I wouldn't even think about bonds. You'll make much more money with stocks and I assume you are young so you have a lot of time to make up for any potential losses.

Max out a Roth IRA with $5500 into a fund you like (most commonly you'll be recommended VTSMX or VFINX) and then take the rest of the cash and invest in a regularly taxed brokerage account.