Is a 1'09 orb between Venus and ASC good?
It means that Venus has a very strong effect on the way your "superficial social mask (Ascendant) appears to others. A wider orb would mean the influence of Venus would be weaker. This is an influence ONLY on your first impression and on your casual social interactions (where you don't know the people well and are not fully relaxed around them). Of course, HOW that Venus aspects OTHER planets determines whether Venus functions smoothly, or with difficulty. The Ascendant is not part of your inner self, and Venus can only work as well as it works with the other planets (the rest of your inner self). So it can be a positive influence on how you come across to others, or it can be a less-than-good. You have to look at the entire chart since everything modifies everything else, and aspects are the most important part of any interpretation. Would it be a first house placement for Venus? Most certainly not. Your first house starts at your Ascendant and extends to some distance BELOW the horizon/Ascendant/First house cusp (you didn't provide the circular chart, so I cannot say exactly). If you have Leo Rising, Sagittarius will be somewhere in the middle of the bottom right side of your birthchart, and not anywhere near the Ascendant (which is the eastern horizon) which is on the left side. Your Venus interacts with (aspects) your Ascendant, and the trine is any distance between 112 and 128 degrees between two chart factors. The exact/partile distance for a trine is 120 degrees, but we allow plus/minus orbs of 8 degrees, so anything between 112 and 128 is considered a trine/harmonious interaction. The closer the two factors are to being 120 degrees apart, exactly, the stronger the influence of this aspect/interaction on your personality will be.