So I stumbled on the MMM site several days ago when I decided to learn a little bit about investing after reading a post on reddit about balancing consumption and learning to invest. I've spent these past few days reading MMM articles along with a few other blogs he has linked to like jlcollinsnh until around 2 in the morning. I am a 20 year old 3rd year college student majoring in English. Over the years I've managed to save well over 10,000 dollars in a savings account, largely because I've worked even though my parents have covered most of my expenses.
I want to put $10,000 into a Vanguard index fund, preferably Total Stock Market Index Fund Admiral Shares (VTSAX), but I have a few questions. Should I make it a Roth IRA or a regular brokerage account (I think that's the term for a normal taxable account)? Or something else? I guess I could start with this year's maximum contribution to the non-admirable version, VTSMX I believe. Then when January rolls around deposit another $5,000 or so and switch it over to the Admiral version. Is it easy to change index funds within Vanguard?
Then once I've graduated and gotten myself an actual job, would I continue to max out the Roth and then put any extra investment-saving money into a brokerage account since as a hopeful mustachian I'll be saving more than $5,500 a year? Should that second account also be the VTSAX or another index fund?
Also should I try to dollar cost average this initial $10,000 investment or go ahead and lump sum it. I know lump sum generally outperforms DCA, but I didn't know if the extra risk should be avoided because this is the majority of my investment money.
Basically I've been inspired by MMM and want to emulate him as much as possible. I just want to make sure I've wrapped my head around everything properly and established a reasonable course of action. Any confirmation or general advice would be much appreciated.