Hi @Devin Miles, great to see other young guys looking to get started in real estate and analyzing deals! Sometimes its a good thing when you post about random properties on the internet because smart NH investors like @James S. and @Daniel C. chime in to give you advice about how to approach (or not approach) a deal. I would echo a lot of what has already been said and add some additional thoughts as follows:
1) This is a nice house with a little bit of income potential. This is not a great rental property. Think about it this way... if you owner-occupy this property and you live in the 2BR and rent out the 6BR, no matter what type of tenant that you find, that's a LOT of people beating on your unit. In a 2BR apartment you usually have 2 - 4 people living in the same space, using the same kitchen, the same bathroom, etc. In a 6BR apartment you have anywhere from 5 - 12 people using the same kitchen, same bathroom, all causing significantly more wear and tear to your unit because of the number of people using it. If you live in the 6BR and rent out the 2BR... well... why do you need a 6BR apartment? You're 19 and probably single or with a partner (unless you have an extended family I don't know about you're hoping to move in) so that's a pretty big house for one or two people. Yes... you could rent it by the room... but the bank won't count any of the room rental income towards your loan amount and also renting by the room is a beast of its own when it comes to investing.
2) The location isn't great for Derry. At a surface level, you're in downtown Derry which has definitely grown a lot over the last few years. However, this property has a pizza shop on one side, a large strip mall abutting your backyard, a house on the other side, and a pharmacy across the street... and you're one door down from one of the busiest roads in downtown Derry. Not exactly an ideal location for a family that's going to be living in a 6BR apartment (back to my earlier point).
3) Adding units is WAY more trouble than its worth. I'll admit, I'm not the most familiar with Derry building codes, but I know pretty well what the basic standard is for places like Manchester or Nashua and usually when you add a unit or take a unit away, that requires you to bring the ENTIRE building up to code; specifically fire code. Because you'll be increasing the density of the building, there's a strong possibility that the town of Derry will require you to sprinkler the building which will not come cheap. This would range from $30,000 - $50,000 in most 3,000 SF properties depending on the layout and need for water. You will end up losing out by attempting to convert this into more than 2 units. And if you did this under an FHA loan your note could be called by the bank if they find out because they definitely do not allow people to make substantial changes to buildings that they have loans on (and adding or removing units definitely fits that criteria).
At a surface level, a 3,000 SF two family in downtown Derry for $350,000 is a pretty decent price. You'd be hard pressed to find a duplex in Manchester or Nashua for the same price point that's a nice property! But there's a reason for that asking price and I strongly advise against anyone jumping into a project that big or that quirky for your first deal (no matter if you have $10K in the bank or $1M in the bank). Certainly don't give up... but maybe change your criteria and keep an eye out for something a little bit more safe for your first house-hack because having a stable foundation in a real estate portfolio is the real path to success in investment... risky purchases with big rewards might seem like a good way to start investing... but unless you have a lot of experience and cash in the bank, its just glorified gambling in my opinion.