Things to consider when buying a paddle are the weight, grip size and head shape of the paddle. Most pickle ball specialists and players emphasize on the weight as the most important characteristic of picking a paddle.
Weight range of paddles:
Light weight: under 7.3 oz / 206gr
Mid weight: 7.3 oz - 8.4 oz / 206gr - 238gr
Heavy weight: 8.4 oz and over
More ball control
Less stress on elbow/shoulders
More strength needed to hit harder/longer
Less effort goes into hitting a harder ball
More stress on elbow/shoulders
Most paddles come with a standard 4 1/4 in grip size. You can always increase the grip size by adding an overgrip but you cannot make the grip size smaller.
There is an official pickle ball regulation on the size of paddles which restricts manufacturers from producing paddles longer than 17in. The wide body shape is the most popular standard shape used by most players. The elongated shape is new to the market and provides a longer reach but smaller sweet spot making it harder for novice players to use.