El infinitivo

Question 1

reasons to use an infinitive

Answer 1

1) to turn it into a noun and give an opinion with the verb “ser” - e.g., (El) Caminar es bueno para la salud.
2) as part of the union of two verbs - conjugated verb + infinitive - e.g., Puedo caminar en el parque?

Question 2

how to use “ir” before an infinitive

Answer 2

ir a . . .