Code must be written inside the body of the class; if you read carefully the error message indicates the same.

https://salesforce.stackexchange.com/questions/301342/lwc1503-parsing-error-leading-decorators-must-be-attached-to-a-class-declarati

【未解決】LWC1503: Dynamic imports are not allowed.

we need to enable LWS under session settings. Setup -> Session Settings -> Enable "Use Lightning Web Security for Lightning web components and Aura components". Also please make sure your in VS code, org-api-version is 58.0 or above. You can check the same using

sf config list

Also, the meta-xml of your component should contain the capabilities property if you want to make use of dynamic instantiation

<?xml version="1.0" encoding="UTF-8"?>
    <LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>59.0</apiVersion>
    <capabilities>
        <capability>lightning__dynamicComponent</capability>
    </capabilities>
</LightningComponentBundle>

Facing Problem in VS Code on LWC Concept

change

@Salesforce/apex/WireApexDemo1.getoppo

to (small 's' since JS is case-sensitive):

@salesforce/apex/WireApexDemo1.getoppo

and as already been said check your java version:

https://www.youtube.com/watch?v=BwBNsLBpnVs

LWC1702

How to fix vscode probrem LWC1702 on lwc's default test.js

I have got the same problem , solved the issue with forward slash

import { createElement } from "lwc/";

import { createElement } from '@lwc/engine-dom';

Adding this resolved the error for me.

LWC1503

LWC1702