It is a slow game and takes time to build up.  

It depends on how much liquidity you have and how quickly you want to build up your portfolio.

Attend your local REI meetups to build up a strong network and feel free to reach out and connect with everyone in the community.

Increase your income, reduce your expenses, save consistently until you build up enough to invest.

Factoring it in to the budget is necessary, but it'll be a while before you build up the cap ex account.

I am looking for Flips or BRRRRs I believe initially to build up some cash and/or equity and cash flow, but would be open to having my strategy/goals challenged.With my previous business, I never took a paycheck and grew the revenue from ~80k to >2million annual revenue in 3-3.5 years and navigated a seller finance purchase of a overlapping/competing business.

Stash the extra money you can save in an index fund like VTI or something that is getting you a good ROI while you build up your equity for your HELOC, this way you're saving up some down payment money while your equity in your home builds. 

Build up your team, prove to agents that you are a closer and they will bring you better deals.

It is also a great way to build up capital for your STR purchases, or blend the two and start doing BRRRs.

Even if you find that you still need money to close, due diligence costs, and some reserves to eek by until you can build up the cash stream.