Learning a language or anything new without difficulties is not possible In my opinion Nathaly. The difficulties are a fundamental part of learning a language and can't be avoided. Making mistakes are the best way to improve our language skills and when we encounter difficulties in learning perhaps with grammar or verb tenses we have to work through those difficulties to gain a better understanding of that language. Learning languages should be a fun and engaging experience using books, games, songs, movies if you enjoy doing something you don't really notice the difficulties you see different opportunities to learn.
I hope this helps Nathaly and good luck.