Learn Spanish (Latin America): Las realidades son distintas, pero continuamos el intento. - The realities are different, but we continue the attempt.

Yes! Both are "adversative connectors," meaning they introduce an opposing idea. You could say Las realidades son distintas, sin embargo, continuamos el intento. The main difference is that sin embargo is a bit more formal and emphatic than pero.

How do I know whether words like realidades are masculine or feminine?

Almost all Spanish nouns ending in -dad (like la realidad, la ciudad, or la universidad) are feminine. That's why this sentence uses the feminine plural article las and why the adjective changes to match it as distintas.

Why use son (from ser) instead of están (from estar) when saying the realities "are different"?

We use ser here because being "different" (distintas) is being described as a fundamental, defining characteristic of these realities, rather than a temporary state or condition.

Is continuamos in the present tense or the past tense here?