Sounds like you have your work cut out for you. I would start with a floor plan. Take measurements of each of the rooms mark where the doors and windows are. Measure the room's dimensions and that of the doors and windows.

Once you have it on paper, take a picture and upload here. Then you might get helpful suggestions.

Good luck!

IMO first you need a budget to share with us. Then get an arcjitect or at least a good designer . I see no floor plan so that is a must for us to even begin to help. Drawit on graph paper to scale and give us info as to what you want from the interior. BTW forget the exterior until you have figured out the interior. You have real issues with the exterior roofing, trim around windows , you need professional help for sure .

Who are Hilary and David? TV actors I assume.

We need the floor plan drawings that came with the sale of the house. Without that we are just guessing.

Here are some basic numbers you will want to keep in mind:

New Bathroom (as in adding a bathroom): $45-55K

New Kitchen (gut and redo): $60K

Create Open Concept living/dining/kitchen: $20K

We are sitting around $130K and we haven't addressed the sunken living room nor the basement. To add windows to a below-grade structure is expensive (new cladding for the house, digging window wells, etc). If you are looking to finish the basement and get it to code then the numbers will continue to jump....very very quickly.

Before we continue to throw weird (and unjustified) numbers at you, you need to post floor plans coupled with room shots.

I do not agree with those numbers I have done many kitchens for a lot less that 60K but we do need info and for sure an idea of your budget.