I'm trying to to "Los Recuerdos de la Alahambra" (sorry if misspelled, based on memory) and need help with the tremolo. Any advice on how to get it fast enough as quickly as possible?
Tremolo is one of those things where I suggest you don't try to aim too fast too soon. Take your development of tremolo very slowly and aim for accuracy and EVENNESS above all else. The speed will come in time.

If you absolutely cant wait and have to have a quasi-decent tremolo quickly, start out with 'speed-bursts' ie play a slow tremolo of quavers (eighth notes) for several bars and then try one bar of semi-quavers (sixteenths), then go back to the quavers. This way you keep the tremolo free and relaxed, but if you try and play tremolo fast for extended periods you risk tensing up.

Good idea, if your serious about classical/flamenco, is to check out 'pumping nylon' by scott tenant. Heaps of classical guitar exercises and technique building, including tremolo.