An organized Nile cruise or guided tour removes most of the uncertainty that can make a first big international trip feel daunting — transport, guides, entrance tickets, and a daily schedule are all arranged, so there's very little to figure out on the ground beyond simply showing up.
The language question
English is widely spoken in tourism-facing roles — hotels, cruise staff, and guides — which further lowers the barrier compared to some other first-trip destinations. See What Language Is Spoken in Egypt, and Will English Work? for more detail.
The payoff is also unusually high for a first trip: genuinely world-famous, tangible history you can walk through rather than something you only read about, which tends to make a strong first impression of international travel.