No, Texas is a proper noun. The proper adjective for Texas is Texan.
Yes, because 'Texas' is a proper adjective (modifying the word 'toast').
Texan "He once crossed the Texan prairies on horseback."
No, it is a verb or a noun (to go around, to surround; a round shape). The adjective form is circular.
It is an adjective.It is a an adjective.
An adjective
it is an adjective!
No. It is not an adjective. An adjective describes something.
Cautious IS an adjective. An adjective is an action!
No, it is an adverb. The adjective is clumsy.
"Good" is a subject adjective. Personally, I would find it very interesting and exciting to drive from Texas to California. Another person might experience the opposite. A journey from one point to another cannot be described as "good" or "bad" without additional information.
It can be. "Ideal" is an adjective and a noun.