I have a plan create non-commercial React SPA like a demo of my skills for own portfolio. Source code of my work will be available on GitHub under GPLv3. I want to use parts of text materials from Wikipedia articles with link to the source like a page content. Can I do these without additional actions and which type of license for text content I should use?
Assuming your SPA doesn't literally depend on this particular Wikipedia content (any content can work and you just choose this particular content because of reasons), then the SPA and the content are independent works as far as copyright is concerned. This means that their respective licenses do not affect each other.
You need to keep the content you copied (and possibly modified) under the CC-BY-SA license and you need to show that license information to the users of your app.
In your repository, you also need to make it clear that different parts are under different licenses (code under GPLv3, content under CC-BY-SA 3.0) and how one can identify what is code and what is content.