If you want to make code changes to the theme files, it is highly recommended that you use the child theme that comes with Innova Construct.
The reason why you should use the child theme is because once new updates will be released to the theme, you will have to just overwrite only the parent theme files to apply the update and every customization that was made inside the child theme will not be lost.
In the themes folder of your WordPress installation, paste the innovaconstruct_child folder via FTP. innovaconstruct_child folder you will a completely changed functions.php(to proper load the child theme) and a style.css where you can add your own css tweaks. To use the child theme, you will have to activate it - go to Appearance › Themes and activate the Innova Construct Child theme. Now any changes you will make in the innovaconstruct_child will be displayed in your site.
For example, you can change the theme's inputs height like this - open style.css from innovaconstruct_child(never delete it's original content) and after "@import url(../innovaconstruct/style.css);" add:
button {
min-height: 52px;
}
By default Innova Construct buttons have a minimum height of 46px. However, adding the above code in your child theme css file, the height will be overwritten and it will became 52px.
Also, assuming you want to make changes to a certain file of the theme, you will have to first copy that file from the actual theme to the child theme. For example, if you want to change the template-blog.php, then copy this file from your innovaconstruct folder(that's inside themes folder) to innovaconstruct_child folder(that's also inside themes folder) and make changes only to the newly created template-blog.php from innovaconstruct_child. These changes will overwrite the original theme files.
If you plan to make changes to a file that is inside a certain folder inside the original theme - for example you need to change template-functions.php that is in /inc, you will have to create a similar folder structure in your innovaconstruct_child theme and copy the template-functions.php in the exact same path.