Learn English – Why does “blue” mood, means “sad mood”

If you see the second meaning of wizard in TheFreeDictionary(same link you have given) it is:

• A skilled or clever person.
• a person who is outstandingly clever in some specified field; expert.

So here 'wizard' meaning is similar to 'expert'. And the same Wikipedia says:

an expert system guides a user through a series of (usually yes/no) questions to solve a problem.

It also states:

The Microsoft Manual of Style for Technical Publications (Version 3.0) urges technical writers to refer to these assistants as "wizards" ...

So the wizard/expert asks you a series of questions to figure out what you want, and then they use their "expertise" to generate a result.

'Assistant' can be use instead of 'wizard'.

Related: Why are wizard dialogs called “wizards”?

"Receipt" is pretty much just an exceptional case. The word is pronounced without a /p/ sound because it comes from French receite/recete. It is spelled with a P based on its etymology from Latin receptus.

It's not entirely random, but it's certainly irregular: the words conceit and deceit have analogous histories, but aren't spelled with P, and the word concept is both spelled with the letter P and pronounced with the sound /p/.

There is a small set of words like this with "etymologically" inserted silent letters. (Most "silent" letters in English are of other types, e.g. the so-called "silent e" that functions in many words as a marker of vowel "length".) Some of the etymologies aren't even accurate: probably the most infamous example is the "silent s" in the spelling of the word island.

Since many people tend to emphasize the "unpredictability" of English spelling in discussions of words like this, I'd like to stress that words with completely irregular "silent" letters like this really are uncommon. English spelling is certainly complicated, but most of the complications are related to semi-regular patterns (e.g. consonant doubling or systematic ambiguities in the spelling of certain sounds), not one-off oddities like this.