Go room by room, take measurements and set a budget. Some ideas below, you may n ot need all the furniture but just some suggestions
Bedroom - bed, bedside tablea, wardrobe, chest of drawers, bed linen x 3 sets, curtains
Bathroom - towels, flannels, storage, soap dish, blind
Living room - sofa, armchair, shelving/bookcase/sideboard/coffee table, rug, curtains, cushions, artwork/photos
Dining room - table, chairs, placemats, storage, table linen, curtains
Kitchen - plates, glasses, bowls, mugs, cutlery, cooking implements, pots, pans, tupperware, curtains/blinds
Cleaning supplies - mop, brush, hoover, duster, cleaning cloths, sprays, polish etc