！！！！！
选择最好的地方很难。我特别喜爱旅行。
世界(instead of saying 世界，we should say 世界上，equivalent to “in the world” in English)有很多美丽的和有趣的城市。我去
到了(到了means "arrived", it's better to say"过了" which literally means 'passed', equivalent to English "had been")不太多(not sure whether you want to say "not many"? if it is, then it's a bit confusing when read the "仍still"in the next sentence, it's not very logical to say i "still" don't know where is the best if i had been to "not many" countries, may be you can change "不太多"to"一些"which means "some")国(国should be changed to 国家，in Chinese, most words appear in two characters, even 国 as a character does mean "country" in Chinese, it's better to used the word"国家")，可是我仍不知道什么地方最好。当我
(is it better to add a "也许maybe" before this sentence? as this is a subjective statement, without "maybe/perhaps" it sounds somewhat arbitrary)去了每个国的
时候(is it better to say "后 after” instead of "时候time")我可以说(it's better to say "我会知道 i will know" which is corresponding to the previous sentence)。
one more thing about the punctuation, as this whole passage is conveying a SINGLE topic, it can be taken as one sentence. So no need to put so many periods.
The corrected version: 选择最好的地方很难，我特别喜爱旅行，世界上有很多美丽和有趣的城市，我去过了不太多国家，可我仍然不知道什么地方最好，也许，当我去了每个国家后我会知道。
