If you prefer to walk into a large retailer, these chains often carry basic baseball equipment in their team sports sections: Sportmaster Sporting goods store OpenSmolenskaya Square, 6/13
Many players recommend ordering online for the best variety, as physical store stock for niche sports like baseball can be limited.
For a deeper selection specifically for baseball players, these locations are known to carry gear: Gloves n' Kit Sporting goods store OpenNizhnyaya Krasnosel'skaya Ulitsa, 35с52