You’ll find the Republic Base in the East Central Courtyard.
The local race, the Selkath, are selling them a special plant with healing properties and they have to put up with each other or risk losing their trading agreements. Two of them are arguing as you leave the docking bay. Manaan is an interesting planet with both Sith and Republican bases. You can persuade your way out of paying the fee if you have the skill. Once you land you’ll be asked to pay another docking fee of 100 credits.
You’ll have another dream on your way to Manaan, showing the location of the Star Map. Main Knights of the Old Republic Walkthrough