Poder is o to ue in the stem, but only when the stress lands there.

puedo · puedes · puede · podemos · podeis · pueden

The trap: nosotros and vosotros keep the plain o, because the stress moves to the ending. So podemos, never puedemos. Every o to ue verb behaves like this: dormir, almorzar, acostarse, costar.

Your class table has a typo: Podeis is written with the accent in the wrong place. The correct form is podeis, stressed on the e.

English has one word "for". Spanish splits it, and this passage uses both.

por for a habitual time: por la manana, por la tarde, por la noche. Your notes make the point explicitly: here por does not mean "because of".

para for purpose: el parque es para jugar.

The trap: "in the morning" is por la manana, not en la manana. And a clock time uses neither: a las ocho.

sin = without, and Spanish drops the article after it: No podemos vivir sin movil. Not sin un movil.

Same in the cafeteria dialogue: sin azucar, sin gas, sin leche.

The trap: after sin, a verb goes in the infinitive: sin hablar = without speaking. English uses -ing there, Spanish never does.