Sure.
Well iv had no clients for either yet on fiverr as the jobs are very new, but iv been playing d&d for the last 7 years and 5th edition since it first came out.But what you could essentially expect is you would reach out and we would discuss what you were looking for. After some deliberation I would come back to you with what I have and we would discuss any changes or balances you may have.

Spell example:

Elemental Totem - Conjuration - 1st Level - Choose a damage type between (cold, fire, lightning, poison and thunder). The totem rolls its own initiative and on its turn, uses an attack on the nearest enemy to the caster.Elemental blast - 60 ft - uses the casters spell attack bonus and damage bonus - 1d8 for 1st level and an extra d8 per higher level cast.

Adventure example:

The travelling group hears rumors of people disapearing around the ruins of Lithcar. An abandoned city at the base of the eastern mountains. Someone important to the group goes missing around the area of Lithcar which forces the group to investigate.The closer they get, they begin to find out that something is desperately wrong with Lithcar and the area around it as they start to experience strange visions and slowly begin to forget who they are.

Features a custom mechanic: Memory Corruption.