automatically shifts into second gear and remain there

Hello,

Shifting issue can be triggered by several different factors. It is always a good idea to make sure the transmission fluid is at proper level and in good condition anytime there is shifting issues.
This can also be due to faulty shift solenoid; a weak transmission oil pump can contribute to this as there won't be sufficient fluid pressure for the transmission to shift properly.

Another possibility is a clogged transmission filter. This can prevent proper flow of fluid and will create this type of shifting issue. So, changing the fluid and filter is a good first step.

Here is a helpful guide to transmission fluid change:

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Please let me know if you have any questions.
Thank you.