Now that I have some funds accumulated around 30k, I was looking at going for a rental property which would make me cash flow positive even if it's a very small number.

I'm still analyzing markets in my area but what is a good estimate of how much capital I should have before I go all in for my search for a multifamily.

I am estimating around $50,000 in work. 

We’d like to get a 3bd place (I work from home and there’s a chance we’ll have a second kid).Savings Rate –If we limit our housing expenses to $5k/month, I’m estimating that we’d be able to save approximately $80k (inclusive of retirement, college savings, and taxable) a year plus 100% of any bonus.As I said curious about anyone that has been in a similar position or more generally any thoughts on what you'd do in our position.

Which area will you be building and what estimate cost per sqft ?

We are purchasing a SFH as a STR requiring work and need budget estimates and someone reliable to do the work as we are out of state investors. 

My initial thought is the best case scenario would be to cash out refinance my current home (i'm estimating $30,000 in equity) and buy another house to do a live in flip so I can rent my current house and use the cash to put towards another house.

So, a quick rough estimate of my expected usage: portland cement to water ratio is 2:1 with no aggregate added, foam to slurry ratio roughly 4:1.

I have an estimated $100k in equity that I could pull out with a cash out refi if I wanted to refinance again and increase my savings to around $150k. 

The quick and dirty formula for a BRRRR isPurchase price = 0.75 * ARV - Rehab CostsIn your case, you would need to acquire the property for ~$156.25k to make it a complete BRRRR deal.Side note, rehab costs are very hard to estimate so make sure you verify that estimate and/or allow for a significant margin of error in your calculations.