Arriving how many days before start date?

Hi! To past auxes (and extremely confident future auxes — you’re a step ahead of me), how many days before the contract start date would you suggest arriving in Spain?

I’m thinking about things like insurance, housing, visa technicalities and adapting to a new city and culture. I’m not expecting anyone to answer all of these questions! But some things I’m asking myself are: Is insurance necessary if you arrive before your contract starts? How long does it take to find housing? Can you enter Spain early on a tourist visa if the study visa is for, say, the first day of the contract? How long do you think is reasonable to adapt to a new environment before starting a new job?

I’m sure a lot of us are deciding what entry date to request on our visas, and when to book our flights! Any insights would be 1000% appreciated! TIA <3