There are some sentences where there are so many kanji present and it is difficult to read at all specially if you're just a beginner. So, is writing sentences in full kana instead of having a kanji acceptable?
(The sample I'm about to give is just a simple phrase that I know has a kanji in it)
For example:
：私はなつです
（watashi wa Natsu desu)
：わたしはなつです
（watashi wa Natsu desu)
Yes it is absolutely acceptable for beginner-level learners to use only kana while they become familiar with the grammar and syntax of Japanese. In fact, this is a very common approach so that people don't get overwhelmed in the early stages. Most learning strategies delay the introduction of kanji until after kana have been learned and then begin gradually integrating them into the learning process. Since Japanese has kana and kanji, the meaning can be understood whichever you use. Of course, standard written Japanese would use a combination of both.
In general, I believe it is better to start using kanji early in the learning process, i.e. as soon as you are comfortable with kana. It is an integral part of Japanese proficiency and can help in other areas like vocabulary acquisition. So although delaying it is normal, I wouldn't advise delaying it too long.
