the contract will usually specify the intended type and base. I have highlighted and underscored intended, because that word should be given much credence. Any contract of employment is offered on the basis that it suits the seller. It will be a condition of employment that you establish a contact address within a particular radius of your assigned base at your own expense. This will often be either 60 or 90 minutes at normal travelling time.
You do not have to set up home at this address. In many cases people will rent a room or share a house or rent accomodation or stay with a local friend or relative in order to satisfy the requirement. The employer will however expect you to be able to report for work and be available on standby from the time established by this address at all material times.
Another point to bear in mind is that work from a particular base may be fluid or seasonal. There may well arise a requirement to change your base (or fleet) as the employers requirments change from time to time. This situation will often arise when the time comes for promotion. Vacancies may only exist at another base and the offer may be conditional on your agreeing to change base. Once established in employment there are often payments available to help offset the costs of such moves, and in some cases there may be tax relief available to offset some of the cost that the employer will not meet. However much of this depends on the terms and conditions you have contracted to.
Naturally as with any contract, you don't have to accept it. However in these circumstances you would be a very confident person to turn down a solid offer. On the other hand if it is going to make you unhappy then there is little point in accepting. Airline flying is an occupation with a global reach that may necessitate you being based in any part of the country. Over a period of time opportunities will arise that enable you to change base, but anybody embarking on this career needs to understand and accept the concept.
I cannot help you with the rosters, since it would very much depend on the airline and the nature of their primary business. Suffice to say you would either be very busy either flying or covering standby's 5 irregular days of the week, or you would be away in hotels a lot.