Padel rackets weights usually range between 340 and 390 grams. Similar to tennis, light rackets are easier to manoeuvre and swing, while heavier rackets allow physically strong players who can swing them effectively to use the weight to strike the ball harder and with greater control.
The racket weight that will be right for you will depend mainly on your physical strength and as a general rule you should pick the heaviest racket you would be comfortable using throughout a match. It should also not be so heavy that you are unable to prepare and take your swing in time.