The language around gender and sexuality changes all the time. It's an area that people hold strong and differing opinions about. As with language around race, disability, and other identities, it’s always best to ask people how they identify rather than assuming.
In general:
Be consistent about how you address people. People in authority are more likely to be referred to by their surname if they are a man, and by their first name if they are a woman. Avoid this by always using someone's full name on the first mention and then their surname after that.
Don't use "he" to refer to an unspecified person – instead use "they" as a singular pronoun without gender. For example:
<aside> ✅ "When the lecturer arrives they will be required to fill out the appropriate paperwork."
</aside>
When using words for particular roles that are associated with gender, consider if you would describe someone not of the specified gender using that term – if you wouldn't, use a different term to describe that role. If at all possible use a gender-neutral term.
<aside> ❌ chairman, chairwoman, housewife, househusband
</aside>
<aside> ✅ chair, homemaker
</aside>
Not everyone identifies as either male or female, and you must be considerate of this.