Should I fill it in capital letters or small letters

You should fill it in small letters with standard capitalization. This means: Start each sentence with a capital letter. Capitalize proper nouns (your name, street names, city names, company names, specific titles like "Hiring Manager"). Use small letters for the rest of the words. Using all capital letters is generally avoided in formal writing as it can be difficult to read and is sometimes perceived as shouting. 3 done, 2 left today. You're making progress.