Basic and beginner is the same. Cast times are the same across the board. Usually a year to master each stage. Advanced is the last stage and at that point is personal styles and such.
Fire.
Basic- Can spark fire,palm size fireballs and less, basic to little fire manipulation(can make the fire into certain shapes and etc) Basic fire user's can generate heat around 500-680 celsius.(Dark red-Bright cherry red.) Cast time is around 10 seconds for fireballs and such.
Intermediate-Can create a spark of fire with a snap,fireballs are roughly half their size, growing grasp of fire manipulation(fire walls, fire shaped weapons,animals made of fire,etc) Basic grasp on fire condensation(smaller,faster fireballs for more lethality) Intermediate users can generate heat around 700-980 celsius.(Bright cherry red-Orange) Cast time is around 8-6 seconds for fireballs and shit.
Advanced-Can spark fire without hands(think human torch),fire balls up to twice their size and growing, intermediate and growing grasp of fire condensation. Advanced grasp of fire manipulation(basically their mana is the limit) and heat is 1,000 celsius and up.(Blue,bright yellow,etc)
Earth
Basic-Can summon clumps of soil and harden it,basic earth shaping,(same idea as fire manipulation, but now with spikes and shit) can only control/shape earth for around 10 seconds. Can only control/shape one piece of earth at a time. Can control around half their body worth of earth in height and weight.
Intermediate-Basic alloy/metal control(beginner level earth shaping but with metal) Growing grasp on earth/soil shaping(spikes, walls, etc). Can control 3, up to 5 pieces of soil/earth and/or metal at the same time. Can control 1 and half of their body height and width at best, just their body height and weight at worst.
Advanced- Complete grasp of earth/soil manipulation and harding(their imagination's the limit.) Intermediate level and growing of metal shaping and growing.(basically intermediate earth shaping, but metal.)
Water
Basic-beginner water manipulation(need bodies of water, same idea with earth and fire with limitations.) Can work with half of their size/height. Basic understanding of water coating(coating themselves for protection).
Intermediate-Better grasp of water manipulation, can work with roughly their body size and destiny, starter understanding of ice shaping and water condensation(smaller=faster)
Advanced-Complete grasp of water manipulation(the body of water and their imaginations the limit.) Can work with double their size and destiny and more as they grow, intermediate level of ice shaping and water condensation and growing.
Air
Basic-beginner level of control(can make a gentle breeze or smth), can float themselves for 2 seconds. Basic levitation of objects, can make something float for 30 seconds, and can be half their body weight. Only one thing.
Intermediate-Better control(stronger breeze or something, can float for 1 minute while moving.) Better object control,objects can be as heavy as they are.(now can hold something for 1 min, at best 1 min 30 seconds.) Basic grasp of throwing objects at fast speeds or adding more speed to a object(around half as fast as a arrow.) Can control 2-3 objects at a time.
Advanced- Complete grasp of control(can sweep people off their feet, make others float, etc.) Complete control of objects(up to twice their body weight, 2-3 mins, 5 min max with basic fatigue.) Intermediate and growing grasp of propelling objects(1x-2x as fast as a arrow.)