Shop / Products all jumbled together.

You would need to update your style.css file, located in your active theme

There are 2 things you will probably want to change
Add

li.product{
    width: 20%;
}

Update – remove the width: 100% from

products img {
    border-radius: 5px 5px 0 0;
    height: auto;
    line-height: 0;
    width: 100%;
}

And to it, for example:

products img {
    border-radius: 5px 5px 0 0;
    height: auto;
    line-height: 0;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

Just an example, you will need to tweak until you are satisfied