Porto is a beautiful town with lots of things to see. One day should not be enough !
The walk from the cathedral along side the Douro river and the ocean to Vila do Conde is great. 30 kms so you could do your walk to Matosinhos as a part of siteseeing , return to your hostal and next day take bus 500 of the metro to Matosinhos and walk from there to Vila do Conde. 20 kms.
From there it is 15 kms to São Pedro de Rates where is an albergue.
From there is some nasty roadwalking to Barcelos but with some safety precautions-fluorescent safetyvest- it is no problem. 20 km.
From Barcelos walk 18 kms to
Casa da Fernanda and stay there for the night .best place on the caminho to stay. Give Fernanda a ring on beforehand +351 914 589 521. It can be busy.
From there it is 14 kms to Ponte de Lima. Stay there for the night. Albergue or several hostals.
Next day is a hard day climbing the off road path to the top of the LaBruja mountain and down to Rubiaes. 18 kms
From there every next stage is about 20 kms except the Padrón to Santiago stage. 24 kms
You could break this distance to 14 kms to Teo where is an albergue and the next day a relaxed walk of 10 kms to Santiago.
Bom caminho