What should I do regarding newspapers that may contain the name of Allah being placed on the ground, and a signboard with the name of Allah in the school next to the football field, and a blanket with "Mecca Al-Mukarramah" written on it that people sit on and place their feet on, knowing that these things do not belong to me? And would I be considered a disbeliever if I am unable to change these matters?

You must be very careful not to give in to obsessive thoughts, as it leads to great harm, and nothing is required of the questioner regarding what was mentioned.

There is no harm in placing newspapers on the ground, and it is not considered disrespectful. If it were disrespectful, such as placing them in a dirty place or stepping on them, then the questioner should advise the officials in the office to find another way to place them.

Nothing is required of the questioner regarding the mentioned sign, as there is nothing prohibited in it.

Using something on which Arabic words are written is not forbidden unless disrespect is intended, and at most, it would be disliked (makruh).

You must strive against yourself to get rid of obsessive thoughts and completely turn away from them.