I have worked with business analyst in my current experience. Skills that business analyst should must have or is having is:

1. They are very at SQL.

2. They are good at handling Excel sheets.

3. They have very good Communication skills .

4. As they have to some time directly talk to customer they should have good language fluent.

5. They are very good at taking and analysing data, for ex. Current growth of users due to some feature release.

Business analysts are one who can use analytics to identify actionable insights for business..

1. Start with learning SQL

2. Excel - specially pivot

3. Communication - Storytelling, presenting and executive presentations.

4.. practice - Start with just reporting and then insights

5. Practice

6. Practice interviews

7. Build network so that you can ask for refferal