Did you read the d̪ et t̪ pages completely? They explain you how to make the sounds. However, if you still want to listen to them, you can go on this page.

For your second edit, you must know that in France, we pronounce it the same way as a normal (french) “a”. Only some rare regions still make the difference, so don’t learn this sound, you won’t need it.

In phonetic, the two triangles ː after a vowell mean that it must be longer, as in english ship /i/ or sheep /iː/.

The sound ɑ is the same as the sound ä described above, but we don’t make the difference and always say it a, except in some regions.

The sound ɔ is the same as in the word spa in english. You can listen to it here again

Finally, I know that the sound œ can be really difficult to pronounce for some foreigners. Again, listen to it on this website, and if you still don’t succeed, you can go on this youtube video.

Good luck!