The QR code is your ticket, but you should not add the journey to you pass and create the tickets until the day the train leaves. You can loose travel days if your plans change. Please read more below. 

For some trains you will need a reservation in addition to your ticket. This you need to check yourself. There are trains with mandatory reservation and trains with optional reservation. 

Seeing PT=POrtugsl-if you want to do the whole trip on the comboio, then you cannot avoid the nasty REServaciones on CP and even more on RENFE in ESpana-and probably also SNCF-TGV in FRancia. Thee can be very hard to get and will also cost extra. You had betetr look into that. If you fly out to cover longer distance, then you may land where this is far more easy