newbie help with home page

That is usually the responsibility of your theme, so contact the theme author for support. (Theme support is out of scope here.) You may be able to do some CSS tweaking with ‘additional CSS’ in the theme. Use the browser’s Inspector (F9) to dig into that area to find the problem.

A splash page on landing page

I would propose first to make this at the front end. The reason is Google and other crawlers can read your content and don’t penalize you for sneaky (the user didn’t expect a redirect) redirects or slow loading times. What I would do: On the main page : function load_splash() { setTimeout(function () { $(‘#hiddendiv’).hide(); … Read more

Home page returns 404

Delete all changes you have done on the .htaccess Make it clean and default to get it OK first, then do the customization. Also try deactivating all plugins and changing your theme to a new one, better get one from https://wordpress.org/themes