Royalty free image is always safe to use for any purpose. That's why people always look for that's kind of image. Well, there are several websites where you could get a royalty-free image like Pixabay,Pexel etc. There you will get plenty of royalty free image but the problem is you may not get your desired image sometime because they have limited stock. In this case, Google will help you to get a royalty free image. Like you need 'long hair' related image but you could not find an image on pixabay then just go to www.google.com then type 'long hair'. like this:-
Then mark on image tab. Like this:-
You can see lot's of image but all are not royalty free image. Then go to setting tab and then click on 'Advanced search'. Like this:-
Then scrol down to at down and find 'usage rights' option. Then mark 'free to use, share or modify, even commercially'. Like this:-
Then click on 'Advanced search'.
Then you will find plenty of royalty free image. That's it.
I uploaded a video on youtube where I showed the process of getting a royalty-free image from google.