Is there a last digit of pi?

Pi has been proven not only to be an irrational number, but also a special type of irrational number, called a transcendental number.

Therefore, when written as a decimal, it has no termination point, so no last digit.

Pi is a really long equation that has no end so people use 3.14 for short

Pi isn't an equation. It's an irrational number, very big difference.
There's no last digit because pi, as an irrational number, will never terminate or repeat since it cannot be expressed in a fraction form.

Some people have dedicated a lot of time to pi, hoping that one day a pattern of numbers will repeat. This would allow them to write it as a fraction but there would still be no last digit. Sadly for them it still remains irrational.