Whether to capitalize or lowercase the first letter of the first word of a quotation depends on how the quotation is integrated into your prose and what appears in the original.
After a Verb of Saying
Capitalize the first letter if the quotation appears after a verb of saying, regardless of the case used in the source–but flag any alterations you make.
A quotation that follows a verb of saying (e.g., writes, says, states, exclaims) and is run in to your text is introduced with a comma and begins with a capital letter.
Published 22 May 2018