Ribeira and the Baixa (Aliados, Rua das Flores, Clérigos, São Bento) are the walk-everywhere core and the first-visit base. River-facing rooms in Ribeira are the most atmospheric and the noisiest, and none has a car park. Cedofeita and Miragaia to the west are quieter and residential, river still in view. Foz do Douro is a calmer Atlantic seafront fifteen minutes away by taxi or forty on the Line 1 tram. Vila Nova de Gaia, across the Dom Luís bridge, has the port lodges and the best view of Porto itself. The Douro valley is a different holiday: about 1h30 to Pinhão by car on the A4, or 2h25 on the Linha do Douro train from São Bento.
The airport is 11 to 15 km north: 20 to 30 minutes by taxi or Uber for €25 to 35, or 27 minutes on Metro line E to Trindade for €2.30.
May to early October is the dry, warm window and the peak. São João on 23 to 24 June is the loudest night in Ribeira and Gaia, and the Douro harvest from mid-September to early October is the valley's most expensive fortnight. November to February is mild, wet and cheaper.
The honest part. Porto is steep, and Ribeira to Aliados is a climb whichever street you take. Ribeira and the Cais de Gaia are crowded from lunch to midnight and noisy on the water side, so ask about room position first. December brings about fifteen rain days, and the Douro is several degrees hotter than the coast in high summer.