Czech R and Ř are not that easy to say correctly. Let's talk about some ways to learn the right pronunciation.
Learn Czech Online:
https://www.e-languages.cz/#english
Mickey's Intro: 00:37
R - Natural Approach: 01:26
R - D to R Method: 04:49
Ř - R+Ž/Ž+R Method: 07:49
Ř - Natural Approach: 11:51
Tongue Twister - 12:28
Mickey's Outro: 12:53