High school in the United states includes years 9-12 of the scholastic development.
In Brazil this corresponds to your three years of technical school.

"some high school" may have several meanings... "some" High School could be saying "I have some (but not all) High School... In other words... example
"I went to school for only 2 years and Dropped out before graduation."

Some high school could also be used to say: "He attends some high school in New York city"... in this case "some" would be indication of a high school who's name is unknown.
Lastly... it could be used to express either a sense of awe.. or disgust...
Example: When hearing what school he attended the girls chided him saying "Wow... that's some high school you go to..."
or after the end of the football season... the winning school could be described with the very same words... but the meaning being positive instead of negative. "Wow!! Now that is some high school!

If this is the answer to the question of "What is your highest level of education?" Then the meaning would be the first example above: "Some High School"; "Some" meaning "less than Graduation" or "I Did not finish High school"
Hope this helps.