If it’s your first time in Barcelona, I’d suggest staying around the Eixample or El Born. Eixample is clean, central, and well-connected (I personally like it for easy walking and metro access), while El Born has more charm, cafes, and nightlife. If you want beach vibes, Barceloneta works, but it can be a bit touristy and noisy. Overall, Eixample feels like the safest and most convenient base for a 3-day trip.