"Character set" and "collation" are related, but different.
For storing International languages, the utf8 character set is recommended.
Once you have picked a character set, then you pick a collation that works with that characterset. See below. Note that latin1 does not handle all the Polish characters.
mysql> SHOW COLLATION WHERE Charset = 'latin1';
+-------------------+---------+----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+-------------------+---------+----+---------+----------+---------+
| latin1_german1_ci | latin1 | 5 | | Yes | 1 |
| latin1_swedish_ci | latin1 | 8 | Yes | Yes | 1 |
| latin1_danish_ci | latin1 | 15 | | Yes | 1 |
| latin1_german2_ci | latin1 | 31 | | Yes | 2 |
| latin1_bin | latin1 | 47 | | Yes | 1 |
| latin1_general_ci | latin1 | 48 | | Yes | 1 |
| latin1_general_cs | latin1 | 49 | | Yes | 1 |
| latin1_spanish_ci | latin1 | 94 | | Yes | 1 |
+-------------------+---------+----+---------+----------+---------+
8 rows in set (0.00 sec)
mysql> SHOW COLLATION WHERE Collation LIKE '%polish%';
+------------------+---------+-----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+------------------+---------+-----+---------+----------+---------+
| cp1250_polish_ci | cp1250 | 99 | | Yes | 1 |
| utf8_polish_ci | utf8 | 197 | | Yes | 8 |
| ucs2_polish_ci | ucs2 | 133 | | Yes | 8 |
+------------------+---------+-----+---------+----------+---------+
3 rows in set (0.00 sec)
mysql> SHOW COLLATION WHERE Charset = 'utf8';
+--------------------+---------+-----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+--------------------+---------+-----+---------+----------+---------+
| utf8_general_ci | utf8 | 33 | Yes | Yes | 1 |
| utf8_bin | utf8 | 83 | | Yes | 1 |
| utf8_unicode_ci | utf8 | 192 | | Yes | 8 |
| utf8_icelandic_ci | utf8 | 193 | | Yes | 8 |
| utf8_latvian_ci | utf8 | 194 | | Yes | 8 |
| utf8_romanian_ci | utf8 | 195 | | Yes | 8 |
| utf8_slovenian_ci | utf8 | 196 | | Yes | 8 |
| utf8_polish_ci | utf8 | 197 | | Yes | 8 |
| utf8_estonian_ci | utf8 | 198 | | Yes | 8 |
| utf8_spanish_ci | utf8 | 199 | | Yes | 8 |
| utf8_swedish_ci | utf8 | 200 | | Yes | 8 |
| utf8_turkish_ci | utf8 | 201 | | Yes | 8 |
| utf8_czech_ci | utf8 | 202 | | Yes | 8 |
| utf8_danish_ci | utf8 | 203 | | Yes | 8 |
| utf8_lithuanian_ci | utf8 | 204 | | Yes | 8 |
| utf8_slovak_ci | utf8 | 205 | | Yes | 8 |
| utf8_spanish2_ci | utf8 | 206 | | Yes | 8 |
| utf8_roman_ci | utf8 | 207 | | Yes | 8 |
| utf8_persian_ci | utf8 | 208 | | Yes | 8 |
| utf8_esperanto_ci | utf8 | 209 | | Yes | 8 |
| utf8_hungarian_ci | utf8 | 210 | | Yes | 8 |
+--------------------+---------+-----+---------+----------+---------+
21 rows in set (0.00 sec)
No collation will work perfectly for multiple languages; there are too many inconsistencies. utf8_unicode_ci may be the best for a mixture. utf8_polish_ci (etc) may be 'better' if you know that all your text is Polish (etc).
Note that "collation" is not relevant until you compare or sort strings -- PRIMARY KEY compares for catching duplicates; WHERE with '>' compares; ORDER BY sorts; etc. For simple storage, collation may not matter.
For further discussion, especially if you need to convert existing latin1 tables to utf8:
http://mysql.rjweb.org/doc.php/charcoll