What you have to do as a business analyst at your first day in the job?

To take into account: 1-the whole organization is an open and adaptable system. Each thing you make will transform the whole system. 2-you must perform elicitation activities from zero minute. But to do that you must be ready. Before you put your feet in the organization as business analyst you have to prepare for elicitation by making the activity to know about the business environment (how others perform in the same business environment). 3-a business analyst is the person that makes dreams comes true to all the stakeholders (or at least make the stakeholders feel that) so that is your focus. You have to deal with stakeholders problems where problem is the gap between perceived reality and desire reality. That means you will work on the perception, you will work on the desire or you will work on the gap. Know your stakeholders. 4-Always remember: a business analyst make diagnoses but not prescribes. Business Analyst must engage the right people to prescribe.

Understanding the organizational processes, network with Enterprise Architecture, determine if there is a centralized knowledge base to learn about other capabilities and solutions within the organization, understand the success measurements, etc....

A lot depends on the organization and its structure. Regardless, you can begin to create your footprint by doing what is right for the business and organization, which is not always with the business wants - negotiation, transparency, communication, understanding, empathy .... all of these skills will provide a pathway to success.

For being a BA, you are looking for some top qualities to exhibit especially for the first job.
1. Make sure you understand the history of the business until date and understand the architecture.
2. Interaction is the key- with business owners and the team, also the PM.
3. Talking persuasively is also vital to make an impression along with technical knowledge.

Hope this helps.