Note some people like Dave Ramsey are good at helping people escape debt, but they're out of their element when it comes to investing. So for investing, you might read something like "A Random Walk Down Wall Street", which is a classic book that is now in it's 12th edition. It's been at every library I've visited, so you can read it for free.
In your position, I would first get allocated to Vanguard Total Stock Market, and then decide on the move to Vanguard.
At TD Ameritrade, you pay $0/trade for most ETFs. So you can buy "VTI" for $0. To see that "VTI" and "VTSAX" are equivalent, search for "VTSAX" and follow the link to vanguard's website. Near the top, there should be a link for the "ETF equivalent"... click that, and you should be looking at the page for "VTI", again still on Vanguard's website. So Vanguard will tell you they're equivalent, and Vanguard runs both of them.
I would suggest selling your single company pick and buying VTI. Putting your entire retirement on the back of one company lacks diversification. What if the coronavirus hit a Carnival cruise ship, instead of a Princess Cruises ship? What if it got out of control, and the company was to blame? Owning just one company means any risk to that company translates directly to your retirement portfolio.
That's why it's better to diversify, and buy the total stock market (like VTI). VTI holds about 3,500 public companies, with more money allocated to the companies that have more weight in the stock market. And if VTI goes down, you know the entire U.S. stock market dropped. Everyone will go through the same thing you're going through, which may also make it more tolerable.
I would switch to VTI first. Later, you can decide about transferring to Vanguard, or staying at TD Ameritrade with $0/trade (same at Vanguard). Diversifying seems more important, and then decide if you want to move the account to Vanguard.