I study on a topic with different algorithms. Can I send two papers to different journals that include same texts. Same paragraphs in introduction or literature review? You can think first paper: "solving problem a with method x". The second paper:"solving problem a with method y". Is it self plagiarism? Also I can't reference the other paper because I will send same time. Should I wait the first paper until published?
This is impossible to judge without a lot more information. The examples you give would not be self plagiarism, since there are so few ways to say what you mean. But note that plagiarism (including self-plagiarism) isn't about words, specifically. It is about ideas. Copying words is about copyright, though using the same words can also imply the same ideas in many cases.
If you write about ideas you've written about before, you need to cite the old work even if none of the words are reused. This lets a reader trace the complete context of the ideas back to the sources, including those you cite in the older work.
But, from what you write here, I think you are worried about minor things.
You can actually cross-cite papers that are "work in progress", especially in initial submissions. Since the first version submitted will almost always be revised over time, you have the opportunity to update those citations. The editor will provide guidance for the final copy if changes are needed.
There are some other situations in which non-published work needs to be cited - even never-published work.