Translation:He will go to Odesa, if there is a train tomorrow.
Correct Ukrainian grammar: he [future] if [future]. Correct English grammar: he [future] if [present]
Example: we will go to the forest (future tense) if the weather is fine tomorrow (present tense).
Wrong: we will go to the forest (future tense) if the weather will be fine tomorrow (future tense, wrong in English)
Because this is type 1 conditional https://www.ef.com/english-resources/english-grammar/type-1-conditional/