To summarize your starting situation:
- Age: 23
- Debts: No car loan, no mortgage, no school loans, no credit card debt.
- Money to invest:$300,000 lump sum.
You want to:
- Every year go on a vacation.
- In ~2 years start/invest in a small business
- In ~17 years go into semi-retirement
No small business
Get a job. Invest the 300K in safe liquid investments then move the maximum amount each year into your retirement accounts. Depending on which company you work for that could include 401K (Regular or Roth), deductible IRA, Roth IRA. The amount of money you can transfer is a function of the options they give you, how much they match, and the amount of income you earn. For the 401K you will invest from your paycheck, but pull an equal amount from the remainder of the 300K. If you are married you can use the same procedure for your spouse's account.
You current income funds any vacations or splurges, because you will not need to put additional funds into your retirement plan. By your late 30's the 300K will now be fully invested in retirement account. Unfortunately you can't touch much of it without paying penalties until you are closer to age 60. Each year before semi-retirement, you will have to invest some of your salary into non-retirement accounts to cushion you between age 40 and age 60.
Invest/start a business:
Take a chunk of the 300K, and decide that in X years you will use it to start a small business. This chunk of money must be liquid and invested safely so that you can use it when you want to. You also don't want to invest it in investments that have a risk of loss.
Take the remaining funds and invest it as described in the no small business section. You will completely convert funds to retirement funds earlier because of a smaller starting amount.
Hopefully the small business creates enough income to allow you to continue to fund retirement or semi-retirement. But it might not.
Comment regarding 5 year "rules":
Roth IRA: you have to remain invested in the Roth IRA for 5 years otherwise your withdrawal is penalized.
Investing in stocks: If your time horizon is short, then stocks are too volatile. If it drops just before you need the money, it might not recover in time.
Final Advice: Get a financial adviser that will lay out a complete plan for a fixed fee. They will discuss investment options, types not particular funds. They will also explain the tax implications of investing in various retirement accounts, and how that will impact your semi-retirement plans. Review the plan every few years as tax laws change.