Money Exchange Info requested

Hi, am traveling to Torrevieja, staying in Punta Prima for 10 days end of June. Where is the best place to exchange dollars for euros. If I use the banks, is the wait time within long for such an exchange. (When I went to Costa Rica, often you have to wait HOURS to get to the head of the line.)

Also, some have told me to bring SOME euros exchanged here in the US to get me started, how much is reasonable?

Also (off topic), is there an significant incidence of crime there, pickpocketing, etc??

Thanks --- looking forward to a great time, never been in Spain. Any other advice is appreciated.

[WENDY]