google search console data shows lots of 1st positions for example but when I check it really in google SERP by my self manually, I see its wrong. Can anyone know what is the reason and how I can solve it? Thanks
The search console reports show the average position for when your page appears in the search results. What is likely happening is that sometimes you are appearing first and sometimes you are not appearing at all. Your average for when you do appear is what you are seeing in the 1st position.
When that happens to your site it is usually because Google is "tasting" your URLs. It is experimenting with occasionally ranking them and seeing whether users have interest in them. Google does this all the time, especially with new sites.