HELOC vs Cash Out Financing For First Time Investor

I am a first time investor looking to use the BRRRR method out of state. I have 100% equity in my home to the tune of about $450k. Should I do a HELOC to purchase my first investment property or should I look to take out a cash loan on my property and use that as the seed money for my first property and then keep rolling it over into new properties. I hope do have 10 doors in the next two years. What are the Pros and Cons of each? I was told by a lender that if I take out a loan vs doing a HELOC, then I have to start paying interest payments on that loan right when I am approved for the loan and accept it. Can't I just get pre-approved for the loan and then access the funds as soon as I make an offer on a property and need them? Thanks in advance for your help here!!