Will taubah (repentance) be accepted in the time of Dajjal? Also, we know from a hadeeth that Dajjal will go around the world for forty days. Will he meet all the people individually?

Yes, the repentance will be accepted at that time, because Prophet (ﷺ) said that the repentance will be accepted till the sun rises from the west.

As for the second question, the Prophet (ﷺ) only said that he will enter every town. Whether he will meet every person individually, we don’t have that knowledge. We just need to get out and flee from the town if we hear about his coming.