Start at Gare du Nord, which is exactly where you want to be for a budget-friendly first night in Paris: the RER B, Metro lines 4 and 5, and plenty of buses are all right there, so getting onward is easy even with luggage. If you’re arriving by train or pulling in from the airport, give yourself a little buffer for station crowds and platform changes; it’s one of Paris’s busiest hubs, and the area around the station can feel fast-paced, so keep bags zipped and move with purpose. If you need to drop luggage, look for a nearby left-luggage service or hotel lockers before heading out, then keep the afternoon light so you can actually enjoy the city instead of fighting jet lag.
For a cheap, local first bite, head to Marché Saint-Quentin in the 10th — it’s covered, practical, and very Parisian without being fussy. You can usually find a decent lunch or early dinner plate for about €8–15, especially if you go for a simple market counter meal, a sandwich, or a quick café-style dish; many spots are open into the evening, but it’s smartest to arrive earlier rather than later if you want the best selection. From there, walk the short stretch to Canal Saint-Martin for an easy post-travel stroll: this is one of the nicest low-cost ways to ease into Paris, with footbridges, waterside benches, and plenty of people just hanging out. The walk from the market is straightforward, and you can linger as long as your energy lasts — no need to over-plan, just drift along the canal and let the day settle.
When you’re ready for a classic first-evening view, take the Metro up to Sacré-Cœur Basilica in Montmartre. The hill is the only part that really asks something of you, but the payoff is huge: a broad panorama over Paris, especially good around sunset and early night. Entry to the basilica is free, and the dome is optional if you want more of a climb and a small ticket fee; either way, this is one of the best low-cost sights in the city. Expect the square and steps to be lively, with street performers and crowds, so keep an eye on belongings and just enjoy the atmosphere. Afterward, drop back down toward Pigalle for an easy dinner at Bouillon Pigalle, where the whole point is solid classic French food at sane prices — think €15–25 per person depending on what you order. It’s busy but efficient, and being close to Metro lines means you can head back to your hotel near transit without a long night ride.