The grout and tile floor in my B.R. Looks dirty What can I do?

Vacuum and spray a cleaner with bleach on the grout, then wipe or mop up.

Try some Aqua Mix grout colorant. Change the color of your grout to a darker color that won't show dirt. Did this in my kitchen and utility in a previous home years ago, what a difference it made.

If you're able to, get down on your hands and knees with a bucket and a scrub brush, hot water with Dawn dish soap and bleach added. Probably 2 cups of bleach to each gallon of water that you use and several good squirts of dawn. Wear gloves. Scrub up the floor and when you are done get a bucket of clear water and clean rags and go over the floor once again. It's hard work but you'll be pleased with the end result.

Try Oxi-clean powder.

You can buy tubes of new color at Lowe's and redo. My grout was too light in my kitchen and that is what I did. You can use a toothbrush to spread it after squeezing a little on old grout. Use a damp cloth to rub off any overflow.

https://abbottsathome.com/change-grout-color-easy-white/