Toilet papers do not expire and can last a long time before you use it.
As long as you keep the toilet paper stored away from moisture and extreme heat the toilet paper will be just fine for many years.
If the toilet paper collects moisture it can begin to mold and then dried out it can become hard.
If exposed to the sunlight or extreme heat the toilet paper may turn a yellow color but will remain safe to use but won't be as good as fresh toilet paper.
Toilet paper and paper towels have no expiration date.
Even disposable diapers do not really expire but as they age the plastic of the disposable diaper degrades and can sometimes get thinner and develop tears in it.
Most people will use their toilet paper well before it has time to go bad but I have used toilet paper that was 10 years old and sometimes older.
A store was going out of business and had a lot of older stock toilet paper that they didn't sell in a long time and so it was marked down to 10 cents a pack to just get rid of it.
I bought some and used it without any issues.