In English, it is very common for the same word to be used as both noun and verb. For example, the verb "trust" can also be a noun, as can the verb "help."
But, except with infinitives, the relationship between verb and noun isn't as straightforward. The noun form for "help" is ayuda, which is very close to the verb, ayudar. The same is true of trabajo ("job" or "work" as a noun) and trabajar (verb). But in the case of "trust," the forms are confiar (verb) and confianza (noun).
About the best that can be said is that it's extremely common for nouns and verbs to share the same stem. Sometimes, as in the examples of trabajo and ayuda, the noun is made up basically of the stem with an ending that marks it as a noun (it's probably just coincidence that trabajo and ayuda also have the form of a conjugated verb), while in other cases the stem is followed by a suffix, as in the case of confianza. ("-Anza" is a not-so-common noun suffix; the related verb is confiar means "to trust.")
In other words, the nouns related to verbs seem arbitrary. Here are just a few examples of some noun forms of common verbs:
- cantar (to sing) - el canto (song, the act of singing)
- decir (to say) - el dicho (saying)
- estar (to be) - el estado (state of being)
- hablar (to speak) - el habla (speech)
- perder (to lose) - la pérdida (loss)
- preferir (to prefer) - la preferencia (preference)
- sentir (to feel) - el sentimiento (feeling)
- tener (to have) - la tenencia (possession)
- ver (to look) - la vista (vision, view)
Good luck finding much of a pattern there! (In most cases, there are also other noun forms not listed above.) Clearly, there are some nouns that are derived from past participles, but it's still unpredictable whether the participle will be modified (as in pérdida) or which gender it will be.
Keep in mind also that many Spanish infinitives can function as nouns, and some of them quite commonly so. For example, the verb poder (to be able) can be used as a noun to mean "power," and saber (to know) can be used as a noun to mean "knowledge."
As you continue to use the language, you'll learn the nouns on their own and you'll no longer have to predict what they might be. Also, if you come across an unfamiliar noun (or verb), you may be able to guess its meaning if you know the related word.