Dumb question(s) about investing profits / taxes

[David Sisson]

Hello, I'm a small business owner (my architecture business) and I also own a couple of investment properties. I hold one of these investment properties in an LLC (that I'm the sole owner of) and the other one my wife and I own jointly. I've been lucky enough in 2021 to build up some healthy profit in both the LLC (real estate business) and my architecture business that I will have some to invest still this year.

I know that I can take the profit, pay no tax on 20%, but be on the hook for tax on the remaining 80%. 

Is it possible for me to (rather than paying myself the profit first) - put the money in the LLC and use it to purchase property directly - IE: an investment for the business? I honestly don't know what this means for my tax liability - I want to get this right - both in terms of the smartest strategy and also following the rules.

I could also - instead of investing in a new property - use some of the $ to improve one of my properties - I have a bunch of it that's awaiting renovation and could then be rented out. I'm not sure if it makes more sense to pay cash for the renovation, or to take a loan to fund the renovation.