Beautiful city. You can also go to the royal palace and the scientists museum, and everywhere to be delighted. Good communication.
Love the vibe in the old town. Venture to the hip street called Nowy Swiat also the newly open promenade along the Vistula river.
The town is a bit sketchy. I hiked all over the place and had a lot of incredible food. After about 40k hike through the national park I saw a drunk guy get picked up by his friends and a block later he was in a fight with the driver. It got kind of bloody the mutual friend in the passenger seat never got out of the car and kept laughing.
Warsaw is huge and really spread out. Most of the tourist attractions are within the Old Town, which at least is walkable. There is a good network of city bikes