Most seasoned solo female travelers say the core skill set is the same worldwide, dialed up or down by destination. Accommodation: pick places with strong recent reviews from other solo women, in central well-lit neighborhoods rather than the cheapest fringe, and hostels with female-only dorms where you want the social side.
For nightlife, the non-negotiables travel with you: keep your drink in sight, set your own transport home before going out, use registered taxis or well-known ride apps at night rather than street cabs or long walks, and be cautious with new acquaintances knowing where you sleep.
On transport, women-only train carriages exist in several countries and are worth using in crush hours; overnight buses and trains warrant extra care with belongings and berth choice. Dress within the local range to reduce attention, share live location with someone you trust, and remember that a loud, confident no plus walking toward other people ends the vast majority of uncomfortable situations.