In simple words
A birth chart is split into 12 houses, and each house is an area of life. The 1st house is about: identity, body, appearance, approach.
Planets sitting in this house in your chart bring their energy to this area of life. An empty house is normal; it still matters. Houses need your exact birth time.
What the 1st house covers
This house covers your body, your manner, your first instincts and the style in which you start things. Planets here colour your whole personality and are easy for others to notice. Its sign is your rising sign, often the impression people form before they know you well.
Growing through this house
Notice the difference between how you come across and how you feel inside. When the two match, people trust you quickly.
Planets in the 1st house
Sun in the 1st house. You lead with your whole self. With the Sun in the first house, your identity is visible from the moment you walk in.
Moon in the 1st house. Your feelings show on your face. With the Moon in the first house, your moods are visible and your sensitivity is part of your presence.
Mercury in the 1st house. Quick, curious and talkative from the start. With Mercury in the first house, your mind is a defining part of your personality.
Venus in the 1st house. Charm is part of who you are. With Venus in the first house, you come across as warm, pleasant and easy to like.
Mars in the 1st house. Energy you can see from across the room. With Mars in the first house, you come across as direct, active and courageous.
Jupiter in the 1st house. Optimism is your first impression. With Jupiter in the first house, you come across as warm, generous and hopeful.
Saturn in the 1st house. Serious, steady and built to last. With Saturn in the first house, you may seem reserved or mature beyond your years.
Uranus in the 1st house. Unmistakably original. With Uranus in the first house, you stand out as independent, unconventional and hard to predict.
Neptune in the 1st house. A dreamy, sensitive presence. With Neptune in the first house, you seem gentle, artistic and sometimes hard to pin down.
Pluto in the 1st house. A powerful, magnetic presence. With Pluto in the first house, you have intensity that people feel.