Do I need to file tax if I work multiple part time as student ? If so How ?

After reading many post about getting higher resident tax and higher insurance bill left my paranoid about reporting my income .

Also some comment in those post say I need to do tax return myself if I have multiple employer .

I know that my part time employer should have withholding my tax but when do I get the withholding slip I need those to declare my income right ? And what happens when I have multiple part time job ?

And I’m very confused about how to file tax return online is is there any guide for dummy that isn’t a whole book to study from ?

Ps it still my first year in japan and all my part time job combine left me around 150,000 yen monthly