Moving to Leeds

Hi all living in Leeds!
We are a Spanish-speaking 40yo couple with a lovely toddler, moving to Leeds in January. We would appreciate some counseling about what city areas are good to rent a cheap flat close to the centre, by a walkable area, affordable supermarkets, etc.
Also would thank very much some useful tips about "how to start" there since I guess some requirements are a must before getting a job (public registers, social security, bank account, university diplomas validation, etc.)... all things you consider can help us to do preparations in advance and avoid making false movements.
In exchange, we offer our friendship and once we are there!!
Thanks very much,
Javier & Margie