You should first identify the actual problem.
If problem is in jquery installation, then you can debug it using following line.
console.log("Jwuery Text : " , $('.testClassName'));
If below log is completely printed in the console then there is no mistake in jquery.
This memory size issue is resolved using reInitialize memory heap by using this command :
set NODE_OPTIONS=--max_old_space_size=4096
or
node --max_old_space_size=4096
After this command run into the command prompt, try to serve project or build a project.