Give me level $0,1$ and $2$ DFD for the below given system scenario also give me structure chart and ERD of the system.

McGregor Institute of Botanical Training is Ireland based training institute located at Godawari, Lalitpur. It has been almost $7$ years since they have been operating in Nepal. It provides different undergraduate and postgraduate courses specializing in agriculture along with horticulture specializations and is affiliated to Dublin City University. Recently, with the sudden surge in the number of people with interest in the domain of agriculture, they are planning to introduce a range of short$-$term certification courses related to horticulture for anyone interested.

Apart from the certification courses, they are looking forward to selling different varieties of plants charging a minimal fee and for free in some of the cases. They want to build a community of individuals with interests in plants and want to create a platform$($forum$)$ where the plant enthusiasts can discuss their ideas, organize programs to protect rare plants and forests. The forum can also prove to be a platform where people can post their queries to be answered by the experts.

Detailed Specification

The proposed system is to have following functions

$1.$ Register in the system.

Any new user should be registered in the system to use the features in the system.

$2.$ Join the program.

Anyone interested can join the program $.$i$.$e graduate or postgraduate or certificate oriented short courses. Courses are both paid and unpaid.

$3.$ Purchase plants

The provision for users to view varieties of plants and purchase if interested. Plants can be kept in carts and bought in bulk.

$4.$ Payment

There should be a provision for the customer to pay and for the plant purchased and the course they are enrolled in$.$ Data of the payment should be stored.

$5.$ Ask for recommendations.

The provision to ask for recommendations with experts. Users pinpoint their site location in the map, if possible, soil condition images and experts reply with the suitable plants$/$crops that can be planted in that particular location.

$6.$ Report preparation.

The facility for the admin to prepare a detailed financial report, employees report and report related to every user.

$7.$ Take certification exams.

Users can take mock tests as per their convenience, check results and also give certification exams after fulfilling certain prerequisites.

$8.$ Forum

Users can engage in conversations about plants, sharing their opinions through posts. They can also comment on and upvote others' opinions.

$9.$ Get Notification

All the different users in the system should get relevant notification according to their activity.