Can you travel from sweden to poland in any ways without passport if your 15 or anyone who can help?...
No. You need a national ID card or passport to cross an EU border - while you might not be asked for it, it's a Schengen requirement to actually carry such a document when crossing an internal border.
Of course, you could drive from Sweden to Poland with a low risk of being stopped. As Jonni says however, the carriers might not be too happy to accept a 15 year old. It does depend though - it is possible to do the journey without an ID card or passport, but if you're stopped, you'll find yourself in trouble.
As far as I know, if both countries are in Schengen, a national identity card should suffice,
Not just Schengen, but in the whole EU (plus some others), the national identity card is enough in lieu of a passport.