Take your errors one by one, and read the messages.
For example:
previous declaration of variable 'STP':Line 10 column 1
So look at your code, and find "STP":
input int STP=30;
...
int STP,TKP;
You are trying to declare the same variable twice: so which one of them should the system use when you reference them later? Which one is later code expecting? Should they be the same variable, or two different ones?
The compiler doesn't know your intent: it just looks at your code and says "I need help with this, what did you mean to write?" And I can't tell you what to do either, because I don't know any more than the compiler does what you intended to do with each variable, or that the second is just spurious.
So fix that, and compile again.
You should expect to get syntax errors every day, probably many times a day while you are coding - we all do regardless of how much experience we have! Sometimes, we misspell a variable, or a keyword; sometimes we forget to close a string or a code block. Sometimes the cat walks over your keyboard and types something really weird. Sometimes we just forget how many parameters a method call needs.
We all make mistakes.
And because we all do it, we all have to fix syntax errors - and it's a lot quicker to learn how and fix them yourself than to wait for someone else to fix them for you! So invest a little time in learning how to read error messages, and how to interpret your code as written in the light of what the compiler is telling you is wrong - it really is trying to be helpful!
So read this:
How to Write Code to Solve a Problem, A Beginner's Guide Part 2: Syntax Errors[
^] - it should help you look at each compilation error and fix it!