Grammatically speaking, the sentence is correct, but its meaning is unclear. The primary issue is that words like endeavor, attempt, and try in the noun form generally need an adjective that indicates exactly what your endeavors were for.
"My minor programming endeavors through my high school kept up my curiosity in computers."
The primary reason it sounds incorrect is because "endeavor" is a noun form of a verb which requires an infinitive. You don't endeavor. You endeavor to do something. In noun form, without the adjective further explaining what the purpose of the endeavor was, it seems vague.
Technically speaking, the phrase is correct without and adjective, but it sounds "off" because it is traditionally used with some description as to what the endeavor was for.
The second issue with the sentence is the use of the phrase "through my high school". The current phraseology implies that you are physically moving through your high school building, rather than progressing through your high school education. Two possible remedies that would further improve upon the clarity of the sentence would be to either drop the word "my", or to add the word "education" to the end of the phrase.
"My minor programming endeavors through high school kept up my curiosity in computers."
"My minor programming endeavors through my high school education kept up my curiosity in computers."
There is another issue regarding your use of "in" - your curiosity is not literally inside a computer, so it would be more appropriate to use the word "toward" or "towards" (depending on whether you're using British or American English), or you could instead say "in the field of computer technology".
"My minor programming endeavors through high school kept up my curiosity toward computers."
I would also recommend changing the phrase "kept up" to something along the lines of "fed", "drove," or "sustained", depending on precisely what you mean to say, but that is a personal choice.