I want to read the Qur'an to get hasanat but my Arabic is bad and I might read wrong and I don't understand most of what I'm reading. What can I do?
You can listen to it from beginning to end many times, in this way you will get used to its proper reading. Afterwards you can start reading along while listening to it, and in this way you reading may improve.
Some people (including many jurists) say that listening to it does not bring the same rewards as reading, but there is no clear evidence for this opinion. Personally I prefer to listen to it with the voice of Mishary al-Afasi. I use an audiobook listening android app (Listen Audiobook Player) that keeps track of my place. It also allows me to speed up the recitation, I generally listen to it at 2.5x speed since this is the most comfortable for me.
As for improving your Arabic comprehension, that requires hundreds of hours of practice. One way you could do it is by using a book of Quran that has the Arabic and the English side by side, in that way you could read one Arabic sentence, then reading the English translation, then read the next sentence. In this way your brain will pick up the meanings of the words even if you do not formally try to memorize the meanings.