Having mastered describing everyday life at A1 and A2, B1 asks for a qualitatively new skill: expressing opinions and discussing broader social issues like the environment, migration, or technology. This is exactly what's tested in the speaking exam's third part (Sprechen Teil 3) of Goethe B1, where you're asked to discuss a topic, not just describe one. The difference between describing and discussing is that discussion needs special connecting language for linking opinions and presenting multiple viewpoints, not just topic vocabulary.
One of the most useful tools is the paired structure Einerseits... andererseits... ("on the one hand... on the other hand..."), ideal for presenting two opposing sides of an issue without immediately taking sides — a technique highly valued in the oral exam because it shows balanced thinking. You'll also need phrases that present an opinion indirectly and politely rather than bluntly, such as Es ist wichtig, dass... ("it's important that...") and Das Problem ist, dass... ("the problem is that..."); note that dass opens a subordinate clause whose verb goes to the very end, just as you learned with nachdem and obwohl in other lessons.
The verb sollen in its Präteritum form, sollten, is used here not to mark past time but to express a polite piece of advice or general recommendation, meaning "should" — a use that comes close to Konjunktiv II in its softness. You'd say Wir sollten weniger Plastik verwenden instead of the blunt command Verwendet weniger Plastik, which sounds harsh in a formal discussion. The pronoun man is a core German tool for talking about a general rule that applies to "people" or "anyone" without naming a specific subject — roughly equivalent to an impersonal "one" or "you" in general statements, as in Man muss die Umwelt schützen ("one must protect the environment").
A common mistake is treating man like an ordinary personal pronoun that can be freely swapped for er or sie, when it's actually an impersonal pronoun with a fixed form only in the Nominativ (it takes different forms, einen/einem, in other cases), and it should never be used to refer back to a specific person mentioned earlier.