What room do you want to paint? What is the "look" you want to achieve? Please give us more information to assist you.
Lots of thing to consider, lighting, texture, size , use of space, what for, outside or inside, what colors are around , trim color, ceiling, flooring, likes, dislikes. Start with a pattern you plan to use in space, it gives you choices.
My suggestion is go with a neutral and add color with decor and fabric. Decide which family of colors you want to go with - beige, gray, greige, etc. Once you have it narrowed down, buy a paint sample. Paint a large section (3' x 3') on the wall or a piece of white poster board. Live with it for a week or so if you think you like it.
How to Choose Paint Color - Sherwin-Williams
Go to the paint store and get a bunch of color cards that you like and pick a few out of the box ones too (you never know). Using painters tape, tape them on the walls of the room you want to paint. Go into the room at different times of day and in different kinds of weather. Throw away the ones you eliminate until you have a few. Go to the paint store and get sample pints of those colors and paint an area with them on the wall. And do the same thing again until you have the one you like for your space.
Look in your closet
What color clothes do you wear? What's you favorite color? It's a place to start.