How do I remodel my 1 bedroom, 1 bath trailer?

The problem with remodeling a trailer is that you have to first identify what structure you are working with. Some come with very minimum size structure and can be very costly to rebuild.

Paint over the paneling , is an inexpensive change. Just be sure to use primer first. Choose a light color for the paint. Keep to the same color in the living, dining and kitchen areas. I would recommend the vinyl plank flooring - the same pattern through out. They make one that is wood tone. Using the same pattern is a light wood tone will make it feel larger. Then use an area rug in the living room area, and bedrooms. For window treatments, inexpensive window shades, with white or white lace panels (to the floor in the living area). Use colored toppers for accent. Keep the color scheme the same in the kitchen, dining and living room area . It will make it seem larger. Keep furniture small scale. A smaller sofa. Club style chair with an ottoman. A small coffee table and smaller end tables. Coffee table can even be a small blanket chest, or fancy wood toy chest (to give you extra storage). Keep to a smaller dining table. Folding chairs can even go under the trailer if extra seating is needed on occasion.

How far do you want to go with the remodel? You can gut everything and start fresh or you can just repaint and put down new flooring.

Yni, this is one of those times that a photo would help tremendously.