But yes, there are many weird sounds in this language which you can't hear anywhere else (particularly "ř") and sounds that are really hard to get out of your mouth when you're not used to it (r, ch ... )

And even if you can pronounce single sounds, waiting for you there are "syllable-making consonants" l and r, which make it possible to form syllables that contain no vowels. Actually Plzeň and Brno are very hard to pronounce right just because they are both 2 syllables (Pl - zeň, Br - no) but contain only 1 vowel. Extreme cases include words like "smrt" (1 syllable, meaning: death). Conjugation suffixes add to this, so you can form words like "trhl" and "zvlhl" (2 syllables both: tr - hl, zvl - hl). Oh, and I forgot to mention words words 0 syllables words () like "k", "s", "v", "z" (meanings: to, with, in, from) -- these are appended to the next word pronounced (they are all prepositions, and unlike English a Czech sentence cannot end with a preposition).