Don’t use text boxes. Text boxes are graphical shapes which are totally alien to any text flow. As graphical shapes, all their properties are frozen at creation time.
What you really need is text frames which create sort of sub-documents (limited to the current page height). Inside frames, all formatting primitives are available, notably paragraph and character styles.
You anchor your frames to the relevant paragraph which refere to them. Don’t be tempted to anchor them to page. This mode is a faux-ami which is reserved for very special uses, DRP-like ones. Anchoring to paragraph means the frame will follow the paragraph when you edit your document and the frame will be laid out in the same page as the paragraph.
Once you have anchored it, you can position it anywhere in the page. Either modify the frame style (go to the Type tab) or right-click on the frame and Properties (go to the Position & Size tab).
In the Position section, choose a reference position. In your case this will be horizontally Paragraph Text area and either Left (for alignment on the left indent) of Fram left with your desired distance.
Choose also a consistent wrap mode in Wrap to avoid splitting your text if not wanted. After is probably your best bet.
