The picture does explain a lot. That is a very low-line crank and the chainrings are riveted in place and cannot be either removed or replaced so you are in for a complete new crank and, most likely, a compatible bottom bracket.

The "For bracket type front derailleur (E)" means the bottom bracket is intended for use with a front derailleur mounted on a bracket that is clamped between the drive-side bottom bracket cup and the frame's bottom bracket shell. This is the configuration used on some MTBs. Most bikes fasten the front derailleur with a clamp or a tab on the frame's seat tube.