Answer:
"Aaron was thrilled when he finally reached to go on the big roller coaster."
Step-by-step explanation:
Your question is a bit confusing because it is not properly spaced out, but I'll do my best to help.
I assume that you want me to correct the sentence, "Aaron was thrilled when he finally reached the to go on the big roller coaster."
If so, then the correct sentence would be "Aaron was thrilled when he finally reached to go on the big roller coaster."