Find free stock photos, crop photos, name them with SEO keywords

I need assistance finding free, stock photos for a website and social media. The photos needed are related to: weddings, money and budgeting, eating healthy and exercising.
Step 2 will include cropping them into specific sizes.
Step 3 will be naming the files with SEO friendly keywords related to provided topics.

I will provide a brand style guide to share what styles of photos I am looking for and what types of photos do not represent my brand.