1. Select your construction ship, then right-click on the selected system. You should see an option to build a starbase, thereby claiming the system.

2. Topaline and Trellium-D each require technologies to extract them, but once researched your construction ships should be able to build mining stations. Additionally, some planets have deposits on which you can build mines as a planetary improvement. Brizeen Nitrate (the game's substitute for Exotic Gases in vanilla Stellaris) I believe is extractable from the beginning. It's my guess that your ships are on auto-upgrade, in which case your designs will automatically outfit your ships with the most advanced technology available, whether you have the resources for it or not. My advice would be go to into your ship designer, and find out which components require these materials. Once those are swapped out, you should be able to build ships with the resources available.

Let me know if this helps!

Yes absolutely. The starbase part especially!

I did the first playthrough with research cheats just to try to understand the UI.

I just started a second one where I'm leaving the research to progress naturally so I can pay more attention to what I'm researching. Very early on there is a technology that allows importing topaline. after I researched it, Topaline was still not available on the market.

Is it a bug, or is it that I don't have trade relations with a species that has Topalione deposits to trade?

Edit: I got it, it doesn't show up in the global marketplace because the tech said unlock import topaline decision so it's just the import decision on planets.

I will look for a planet with brizeen nitrate.

Cheers

Once I got the tech to mine topaline, I found a nearby system with a planet that has it, and once I built a mining station there, it showed up for trade on the market.

and I realize now the global market isn't the same as the local market page, there's a subtle little arrow to switch between them (at least on the federation interface it is subtle).

Thank you very much

Originally posted by Kitty Pryde:

Once I got the tech to mine topaline, I found a nearby system with a planet that has it, and once I built a mining station there, it showed up for trade on the market.

Thank you very much

No worries! For brizeen nitrate, I'd try your homeworld to see if it's being produced already. Alternatively, there should be unlockable technologies for a building (fertiliser collector or something similar) to produce it.