Hi recently I got a dean ml and it's a fantastic guitar but I noticed that there is a lot of fret buzz on all the strings from the 1st to 3rd fret. All the other frets are fine and have no buzz. I tried raising the bridge a bit more but that didn't help. Also the neck is perfectly straight.

What should I do to take away that fret buzz by the way it's a floyd rose guitar.

If it's perfectly straight, then that's the problem. Add some relief to it.
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This^ The neck should bow forward, as in the headstock moves forward towards the pickup side of the body. Tighten the truss rod to do this. Leave the strings on. Tighten a quarter turn at a time and check to see if the buzz is still there. If it's worse go the other way. If it is better keep going while checking each quarter turn.

Use common sense. It should never be hard to tighten the truss rod. If it takes very much pressure to turn it is probably full torqued. Same for loosening. You don't want to decrease tension to the point of lose play.