Hope you are doing well and sorry for the trouble. As described you are unable to fill in the PDF forms and add text . Also as mentioned the white color isn't selected.
What is the version of the Adobe Acrobat DC you are using. To check the version go to Help > About Acrobat and make sure you have the latest version 21.01.20145 installed. Go to Help > Check for updates and reboot the computer once.
If it still doesn't work, please try to repair the installation form the help menu. Go to Help > Repair Installation.