I keep on clicking on the MD files in the File Explorer, but when Obsidian opens it opens on a new vault with “welcome this is your new vault.”
Things I have tried
I’ve looked elsewhere on the forum, but I can’t seem to find any similar issues.
Let me know if I’ve misinterpreted: Sounds like you’re opening the markdown file from your operating system’s file explorer, and you’ve maybe set Obsidian as the default app for md files.
Clicking the markdown file in your system browser does not (at present, anyway) open specifically that file in Obsidian.
To open an arbitrary file within in Obsidian, you have to either open the file from Obsidian’s file explorer, use a URI (from inside or outside of Obsidian), or choose a relevant behavior in Settings > Files and links > Default file to open.
oops, left an explanation without a workaround
Open Obsidian from its icon or the start menu.
If that opens a vault that isn’t the one you’re looking for, then on the bottom left, click the name of the current vault to open the vault switcher: if your vault is listed there, select it; if it is not listed there, then select Manage vaults....
In the window to manage your vaults, click Open to “Open folder as vault”. Navigate to your vault folder (the one that contains the .obsidian folder) to open that as your vault.