ありがとう! I watched blue box even though I don't really like sports anime

It's better to focus on either japanese or Chinese. Yes, the sound is very different, but I think it's very likely to mess up
汉字 and
漢字 and on top of that your pace will slow down especially with two difficult languages that take years to reach a high proficiency if you learn them even seperately

And it will take much much more longer if you are not motivated to study

But of course, If you can handle both at the same time and if you are motivated you can learn them as you want

I also want to learn Chinese and Korean but I will do it one by one