How to change image size and position when uploading to article in tb_rave_starter
To edit the size of the image:

Go to /admin/structure/types/manage/YOUR_CONTENT_TYPE/display and click the edit image style button shown in the image below.



This will open a drop down and then you can choose the image size you want:



To change the location of the image you have several options...

You can edit your themes CSS file, however this will require understanding the underlying HTML and CSS.

An alternative is to use a module like Panels that allows you to create custom layout and apply them without actually doing any coding. I've not actually used it before myself but have heard good things about it and there are lots of tutorials online - just Google it.