For most of your questions about residency during the transition period and the new residency procedure.
FAQs in English from the Spanish Government in the link below:
CAB notes.
1. In reference to Freedom of Movement (FOM) mentioned in this paragraph;
If I am a beneficiary of the Withdrawal Agreement, I am in possession of a residence document issued on the basis of that agreement and want to move to reside in another EU country, can I do so?
The Withdrawal Agreement recognises the right to reside in the host country, however future mobility will be subject to negotiations within the framework of the future relationship between the UK and the EU. Should there be a lack of agreement in this matter:
For short stays: the rules for short stays within the Schengen area apply
For stays longer than 3 months, the national legislation of each EEA shall apply.We suggest that you read the section on FOM on the post below
For those who feel they would like to use a lawyer for the application or any other legal matter, can enter the link below for a CAB corporate partner.