@Account Closed Welcome to BP! I am also a newbie, but I wanted to bring up a point that hasn't been mentioned yet: exit strategy. As others have said, HML are short term use, and it seems like this multi you are looking for is something you'd want to hold as a rental. The problem in that case is that you won't be able to refinance out of the deal once the rehab is done in order to pay back the HML. When you refinance you'll usually be able to get about 60-70% of the ARV, which won't be all that much higher than your PP because you won't be doing a large amount of rehab. You'd have to find a very good deal in order to be able to refi out enough to pay back the HML.
Just for example, I've been running models that use that mode of financing, however (at least in Vegas), I have not found deals with enough meat on the bone to use HML to BRRRR the property. The only viable deal I have found in which HML would be a good route is in a property where the rehab costs will be about 3% of the ARV, and the property is selling for about 70% of the ARV. The general rule I've read is that you should pay no more than 70% ARV minus rehab costs. In this case it's close. But even then, I know I would not be able to refi out enough to get a HML repaid, so I would have to flip the property and the final profit out is 12k, minus the points + interest paid to HML and the cost to sell. This isn't a huge margin, and if something comes up then it could cost me to flip. The other option is to use a conventional loan but hard money/private money for the down payment. This may be a better option for you as well. You'd just need to find a way to qualify, like getting a great cosigner (pay them to sign with you), or by getting help from a parent or family member(money or HELOC on their home?), maybe even finding a partner.
As others have stated using an FHA with a 3.5% down loan sounds like the best option because of the fact that it is a multi and you could live in one unit for a year and rent the rest. The 203k actually allows for a rehab budget. It's just a matter of whether you still cash flow with the PMI. Even if you don't cash flow, it may be worth it to pay a small "rent" for a year just to be able to refinance out of the FHA (if you have enough equity at that point) to where you start to cash flow.