After getting the address and seed phrase, it is stored in a safe place, then the application is uninstalled. Is that the right way?
Well, I think the security concerns have been mentioned above so you can decide whether that's a good thing to do or not. I don't recommend doing that if you eventually switch to cold storage to store your crypto, might as well use an air-gapped device, to begin with.
i am going to say something totally irrelavent to this topic, i am newbie and there is no guide or straight to the point explanation how to post here or start a new subject,
There is a pinned thread on this sub-board that probably answers most of your questions as a newbie[1]. Check the Meta board too if your question is related to how to post/navigate the forum.
[1]
https://bitcointalk.org/index.php?topic=1689727.0