What language server are you using? Please post your Packages/User/LSP.sublime-settings. Or join the Sublime Text Discord server (channel #lsp) to get more direct help.
Similarly to SublimeLinter, the long-term strategy for LSP is to move towards helper packages, because set up can get quite complex for some language servers, even requiring writing some extra python glue code.
The designated helper package for JavaScript (as well as TypeScript) is called LSP-typescript. This package will install a local server for you, set up the appropriate client connection settings, and also has some client glue code for not starting the server sub process when you don’t have any folders open in your window (because the server will throw a hissy fit if it doesn’t receive any folders, despite this being allowed by the underlying protocol).