The goal here would to help educate and avoid potential pitfalls before wiring $50,000, $100,000 or even more.We would have educational modules, regular meetings and ZERO solicitation. 

I agree with the others on the LVP and avoiding carpet if you can.

I have started raising rents to market rent one unit at a time to avoid a total tenant turnover all at once.

Can anyone give me one advice or one mistake to avoid as  I look towards getting started?

Given your experience and strong financials, you have some solid options:Commercial or Portfolio Loan: These are tailored for investors and can help you avoid personal guarantees, especially since you have an LLC.BRRRR Loan (Buy, Rehab, Rent, Refinance, Repeat): Some lenders offer BRRRR-specific loans with funding for purchase and rehab, allowing you to refinance based on the new ARV once stabilized.HELOC or Cash-Out Refi on Current Rentals: Tap into the equity on your single-family rentals to secure funding for the 4-plex purchase and rehab without high origination fees.Each has pros depending on your cash flow goals and timeline.

The general reason (avoiding any personal thoughts on wholesaling as a business) is that when you have a license, any fee you get for transacting or assisting in real estate must go through your brokerage and they must take their percentage.

and some areas to avoid ?

This helps to avoid conflict.

I want to use her equity as a gift for the down payment to avoid capital gain taxes.

Joseph,Bigger Pockets is the best site on the internet to build a newtork and get all the hlep you need to avoid mistakes and save money!