There isn't a single foreign unit in Ukraine.
International Battalion is easy to get into but they have a reputation for subpar leadership and often being used in suidical operations.
There was this one convicted Polish rapist who fled Poland to evade the law and somehow ended up leading a larger volunteer unit. Often sending entired platoons into suicide missions with no survivors and ordered his subordinates to loot (war crime) because he is a retard. Wonder how no one shot him, officers got shot by their soldiers in Vietnam for less.
There are better units but most of these only take you if you were a soldier before or already fought in Ukraine for some time.
Bolivar Battalion exists for people who speak Spanish and you are probably better off there than the international unit. Knowing both English and Spanish is a big plus. However since you have no prior experience, your unit choice is very limited.
Either way you will fight in a pretty gruesome conflict where you will experience many dead and wounded in your unit. Due to drones and artillery, personal agency is lower so your death may come in an instant and there is little you can do. Additionally you can also receive some nasty injuries that really mess you up and death may have been preferable.
Only go if you are willing to sacrifice. Otherwise there is no point.
French Foreign Legion works for starting a new life and you won't get deployed to the worst war zone since the Iran-Iraq War. They will probably ship you to Africa instead to shoot jihadi niggers.
They do have pretty tough tests to get into but it is more mental than physical.
Examination is extensive and they will aks you questions like "Why didn't you join the Spanish military?" and more. You also need to show them that you REALLY want to be part of the unit.
US military only takes you if you have American citizenship or residence permit. Maybe write Trump and Musk an email and you will be given one if you promise to join the Marines.