Getting nowhere in twenty twenty two

I have been struggling with CSS all day.

Cannot for the life of me find anywhere is the theme to modify the CSS.

I am now using the plugin but get nothing but expected this or expected that.

I need to accomplish two things:

1. I need to add code that will get my images to align and center properly throughout the site. I believe I need to add this: .elementor .elementor-widget:not(.elementor-widget-text-editor) figure.aligncenter {
margin: 0 auto;
}
2. I have added captions to my images but I would like them to display throughout the site at no larger than 8 px. Thought I had code for this, but it doesn’t work:

body {
    background-color: var(--wp--preset--color--background);
    color: var(--wp--preset--color--foreground);
    font-family: var(--wp--preset--font-family--system-font);
    font-size: font-size: 8px;
    text-align: center;
    line-height: var(--wp--custom--typography--line-height--normal);
    --wp--style--block-gap: 1.5rem;
}

Any help that anyone can give would be greatly appreciated.

Thank you,

Robert

The page I need help with: [log in to see the link]