Boot problems after Elementary OS installation

Dear community,
I am not very professional in Linux , I just start my first steps. I had Linux Mint 20 XFCE, that was loading from the USB tf card adapter, and Windows, that was loaded from the internal storage. Yesterday I decided to test Elementary OS , and set up it on the another tf card that was in USB tf card adapter.
In the morning I was trying to start my Linux Mint , and when I choose any options in the startup menu rather than Windows in the BIOS, I starts with a
Then I choose Windows and start the system,
And now I can’t get into the BIOS. Previously I’ve got there with a long ESC button pressing.
What I’ve done wrong, and how to fix it?
I’d like to have ability to load different OSes from my USB tf card adapter.