Paris
Good to know before you go
As with any major city, Paris is expensive. This means you can expect to pay minimum 20 euros for meals, breakfasts, brunch etc. Coffee cannot be found for less than 4 euros, and drinks are likely 10 euros or more, this is the big city life... I cannot even imagine the prices in the more touristic spots.
Yes it's a stereotype but for a reason: English is not widely spoken. Of course in touristic areas people speak English but often reluctantly. You will probably find it hard to get decent and easily accessible information from people in English. Just be prepared and either practice your French or download Google Translate, and arm yourself with patience.
Last but not least, Paris is perhaps not as safe as some of the other major European cities. Beware of pickpockets and petty theft, just keep your belongings close to you and pay attention to what's going on. Late at night and especially solo female travellers, consider Ubers rather than the metro or RER. Get a feeling for your neighbourhood as well, so you know how you will feel comfortable coming home.
Getting around in Paris
There is a good public transport system, and bicycles are also popular. However: