I need help

You can either break it up into 2 pieces or leave it whole.
I am the queen of chicken....

If you are only cooking that one chicken breast, you need to get a baking dish or something to bake it in that is a few inches deep.

to the dish...add enough water to cover around half of the breast. add some chicken base or several chicken bouillion cubes and some salt / pepper / and other seasons if you prefer...i usually also add random stuff like poultry season, mrs. dash, or whatever..
bake at about 350 or 400 for maybe 40 minutes and then turn the chicken over to expose the part that was in the water. cook for maybe another 40 minutes and see what the chicken looks like...does it look done? if not...flip it over again for maybe 20 more and keep doing this until the chicken is done.

You can also add stuff to the baking dish like baby carrots, mushrooms, two halves of onions...just for some cooked vege sides. The veges will cook and marinate in that chicken base while cooking. My family loves when I do this.

You can also just put some spices on it, wrap it in foil, and bake.

Brine it ( 1/2 cup kosher salt or 1/4 cup table salt with enough water to cover the chicken breast) for 1/2 hour.

Pat dry and season with pepper. If you have the ingredients, brush with mustard and cover with fresh bread crumbs moistened with olive oil.

Bake at 400 for about 45 minutes.