Question from a 1200 rated player

Sorry if I am disturbing, but I need help with my middlegame strategy. I am currently following middlegame principles from GM Igor Smirnov's masterclass where he teaches us to attack, plan and improve pieces. However I am confused on how to balance making plans and limiting opponent's plans. I find that once my opponents start their plan, I am absolutely demolished. Also, I need help evaluating the weaknesses of the opponent's board. Pls if you have any tips, or maybe sources for me to learn from, I would be grateful! 🙏