You can expect massive crowds, and you should be aware of any processions because you can be trapped in a "bulla" for hours if streets are closed. You need to be aware of the dozens of processions and either plan to watch (and possibly be trapped, and be far back in the middle of the crowds) or stay far away from their routes.
Streets closed, taxis routed away from them---you might not be able to get where you are going..like to a restaurant where you have booked.
Cathedral/Calle Sierpes area will probably be the most affected but the brotherhoods' routes go all over the center. it's super important to have a map and note the times.
I would book restaurants as far ahead of time if there are specific places you want to eat. Many restaurants have special fixed Easter meals for the main meal of the day, and will be closed Sunday night, as is normal.
Shops should be open except for Sunday, I imagine, but what kind of shopping do you want to do in Sevilla?
If you are not going to see the processions, I would stay away from Sevilla during that week.
I'm assuming that's why you are going at that time, right?