New young investor looking for some advice

hello everyone. I'm fairly new here but have been educating myself because I want to get involved in real estate sooner than later. I have been taking steps to work towards that goal. I have a house that I have been living in for the last few years with a 10 yr mortgage. I have built equity in the house and will be closing on a heloc today. I am using santander with 90% ltv which gets me 88k. I was planning on doing some flips to raise more capital with long term rentals as my end goal. a few weeks ago I was driving through town and found a 2 family house for rent. I called the owners who are elderly to ask if they are interested in selling. I had to call once a week for 3 weeks before I got to talk to the husband who said they are retired in Florida and that they would entertain offers. When I asked for a price he said 350k. the units are each 2 bd 1 bath. They have a long time tenant who pays 1450 a mponth and they are getting another tenant in the other at 1550. utilities are paid by the tenants except for the water bill I believe. I'm not sure what the taxes are but I would think between 6-7000 . from the outside it looks like it could use some updating. I do have some money saved up other than the heloc but would like to try to possibly do a brrrr using the heloc as down payment on a 30 yr. I am just looking for some advice if it is a good deal and maybe some ideas on creative financing. thanks