There is a red warming filter that you can use to take the blue tint out of ambient light shots. But remember, any time you put something in front of the lens, you take up light for exposure, and maybe have sharpness issues too. In ambient light, reds and the warm spectrum of light drops off first, then works it way down to the cool spectrum.
The stobe will really help, just get one with a removable diffuser on it (most have this). Do everything you can to keep the stobe angle off the angle of your lens (i.e. don't shoot with the stobe straight into the same plane as the lens). This causes backskatter, and you will have dots all around the image.
Start off simple, then work your way up to using more advanced items. No sense in trying to shoot with a lot of technical gear to begin with. Keep at it, you will get it. Safe diving to you. Post your shots.