What is Ukraine's strategy to fight Russia?

There is a scene of devastation in Ukraine. Cities are turning into ruins. The streets are deserted. The situation is that neither Russia is stopping the attack, nor is Ukraine giving up. In the midst of this war, many thoughts are coming out. What is the result of this war between Ukraine and Russia? The war started with Ukraine joining NATO. Russia is making its new strategy every day. But the big question is what is Zelensky doing, what plan has he prepared to fight.