The ㅈ sound doesn't exist in English. It falls somewhere between "j" and "ch". "j" is a voiced vowel, which Korean doesn't have besides ㄴ,ㄹ,ㅁ,ㅇ, so ㅈ is usually considered closer to "ch". To make an accurate ㅈ sound, you take off most of the sharp aspiration from "ch" by pulling back the tongue slightly to reduce friction, and at the same time tense the throat area to make the sound heavier. For "ch", the tongue becomes relatively flat so that the sides of it add to the friction, but for ㅈ, the tongue stays more round and there is much less friction. You might say ㅈ is like an unvoiced "j" or unaspirated "ch", but it's hard to describe the sound in words. Overall, "ch" sounds sharp and light, pronounced mostly in the front of the mouth, whereas ㅈ is dull, gruff and heavy, and sounded further back in the mouth. The vowel ㅊ is much closer to "ch" because it's pronounced likeㅈ except that it's heavily aspirated. For example, 암체어 is listed in the dictionary for "armchair". The actual sound of "chair" is probably more like 쳬어 or 췌어, but the spelling rules standardize on 체어 and discourage unnecessary proliferation of less used vowels like ㅖ and ㅞ to keep things simple and easy.

The ㅈ in [제] 이름은, [저]는, [자]다 sounds like /tɕ/ (Voiceless alveolo-palatal affricate) The ㅈ in 아[저]씨, 어[제],편[지] sounds like /dʑ/ (Voiced alveolo-palatal affricate) The ch in cherry sounds like /tʃ/ (Voiceless postalveolar affricate) The j in Jerry sounds like /dʒ/ (Voiced postalveolar affricate) The sound /tɕ/ is neither /tʃ/ nor /dʒ/. But /tɕ/ is closer to /tʃ/ than /dʒ/

It sound like "Jerry"