I would create custom thumbnails for your videos if you want a chance of drawing in an audience. They're easy to make and there's websites that let you create them for free (canva.com).
Look into adding the "vidIQ" extension to your browser. It's a free tool that helps YouTubers on many things like giving you a more comprehensive view of how many views you're drawing in and which tags to use on your videos to draw more people to your content.
Welcome to the forum. Would love to look at your channel but there's no link. Luckily it's an easy fix = can put channel link under name(age) as seen under mine to the LEFT of this msg - read my signature on HOW TO below this msg