@Dave Meyer has a great book about strategy you can get here on BP.  

MTR's are a GREAT rental strategy.

But you can never know the exact best time to sell (or buy).When price corrections happen:      1)   Some investors will lose their properties due to no cash reserves, or no credit reserves.      2)   Some will lose them due to lack of knowledge or not having a market appropriate strategy.      3)   Some of them will lose them because they over-payed, or bought negative cash flow properties, or bought properties they don’t know how to manage (or have a good manager for).Good Luck!

I have a lot of clients interested in the BRRRR strategy, but struggle to find properties that can cash flow from this strategy.

@Joseph Fenner, so many people forget that the first step of implementing the BRRRR strategy is acquiring the property all CASH.

There is a fantastic group call WREN (Women's Real Estate Investors Network) It's essentially a REIA for Women to swap ideas, share stories, network, etc.

Something to keep in mind while you renovate: I suggest you have multiple strategies planned out and what your outcome would be if you had to pivot for some reason.

But, they are questions to answer on your own that could help lead to to a strategy. 

Without getting into too much detail, you are essentially setting the value of the triplex with the purchase itself (in the lenders eyes).  

If you are not afraid of the Lawyer/Accountant factor .... your Dad could partner with you on a deal with a lot of first year deapprectioation to offset some of the taxes from the 401k w/drawal.It's time to get a really good accountant that loves strategy.