How do I change the size of the image on the home page using Soho theme?

You can adjust the size of the header image by adding the CSS code below by clicking Theme->Customize->Advanced->Add CSS.

body.homepage-view .hero-image.has-image {

    height: 62.5vw;

    max-height: 75vh;

    min-height: 200px;

    width: 100%;

}

Please change the height, max-height, min-height and width to meet your needs. 

Also, adding the code below for post image:

.snippet-thumbnail img {

    width: 100%;

    height: 100%

}

Again, please change the width & height to meet your needs.

After that click Apply to blog.

How to insert photos from Google Drive into Blogger?

1. Goto photos.google.com
2. Click at menu.
3. Select Settings.
4. Turn on Google Drive - Show Google Drive photos & videos in your Photos library.
5. Wait for a while for #4 to take effect.
6. Goto Blogger.com
7. Create a new post or edit an existing post.
8. Now you can insert the photo by clicking at the insert image menu next to Link.
9. Click at From Google Album Archive then you can find the photo in Google Drive. (If you cannot see the photo from Google Drive, please wait a little more time.)
10. Click at the photo you want and click Add selected.