@Timothy Brolsma hi Timothy and welcome to BP. Being a remodeler is going to come in handy because you will be able to save a lot of money by doing your own work at first. But I do have to say that investing isn’t easy and can be quite stressful.
I personally would not put the house in an llc. First since you have a mortgage ok it technically the bank can call it due if you quit claim it, I’ve never heard it actually happen but it’s a possibility. Also your insurance will go up and if you refinance into an llc you’re more limited with banks and your interest rate will again go up.
If you want to pull money out of your house you should work with a realtor (or pay for an appraisal) to get an estimated value. Then you should see how much you could pull out and what your payment will be at. For investment properties I’m seeing 6.99 from mortgage brokers, so your rate will probably double. You will have to see if rents for your current house would cash flow with these numbers. If not it may be worth waiting to refinance until rates come back down. Since you want to start house hacking you don’t need a lot of money to start. You can get into a duplex with 5% down (can do 3.5% fha but most duplexes don’t qualify)
Since your girlfriend's property is a condo you will have to verify with the HOA that they allow shot term rentals. There are not very many that do so I would assume they probably don't allow it. You would also have to see if they allow rentals in general, which again not a lot do. If they don't allow rentals it might be worth selling and using those proceeds. Let me know if I can help out any more