Girls, hi. Help me, more precisely tell me) we start introducing compl…

Girls, hi. Help me, more precisely tell me) we start introducing complementary feeding. I bought a can of zucchini, how to introduce it correctly. I understood that on the first day one teaspoon, the second two, the third three and so increase. On the can it says that after opening store it for no longer than 24 hours. This means throwing out three teaspoons? It's kind of sad, of course.