is "to prepare" in the sentence One to make ready, and two to prepare, an infinitive?

Answer 1

Yes, all verbs, preceded by "to" are in the infinitive: an attempt TO DO; try TO MAKE; know how TO SWIM; want TO GO OUT, etc.

After prepositions (of, at, etc.) one must use the gerund (-ing): to congragulate someone ON doING something; to apologize FOR sayING something; to start the class BY sayING ..., etc.

A great number of verbs may take either the infinitive or the gerund:love, hate, propose, like, prefer, start, begin, fear, intend, omit learn, etc.

Answer 2

Yes