you can and have to show all your activities in the past whether they are or are not related to studies -- leaving out information that may affect an officer's decision is misrepresentation. In this case, not reporting your employment (even if temporary for 3 months) is risking misrepresentation if they ever find out.
this is specially true for you as you reported you were basically unemployed (or studying for IETLS or whatever) although you did have some sort of temp job.
Anyways, lets assume that doesnt matter.
So you graduated highschool and then remained unemployed for xx amount of time (preparing for IELTS doesnt count). this is understandable through covid, its been rough for everyone.
So your letter of explanation/purpose etc has to be extremely convincing that this program will further your career prospects in your *home* country. NOT in Canada or Spain or aywhere else. The onus is on you to prove you will return to India and work there (even if most ppl stay here after studies). You will have to explain that due to covid you accompanied your parents in Spain where you were not able to study/work due to langauge barriers and instead prepared to study abroad by studying your IELTS.
Honestly, its a tough one, and above my paygrade. I hope someone else can chime in
