Ok, I have both maps 1 and 2 but I was wondering what level I should be before I go there and how hard it is in comparasion with Vvardenfell and the expansions.
Thanks

Unlike Mournhold and Solstheim, the TR maps are pretty safe regions. You should be able to walk around just fine at any level. Outside you'll mostly find low level creatures and bandits. It'll be more dangerous in dungeons and such but that should be comparable to Vvardenfell difficulty, not Mournhold/Solstheim difficulty.

While I can't speak from experience, it is my understanding that the spirit behind TR does not include creating content designed for higher level players, but for simply expanding the landscape and filling it with stuff that fits the province of Morrowind. If some of it is more challenging, which I'm sure is the case, it's probably little or no more so than any challenges in the vanilla game.

Then again, I've never raided their ruins/tombs.

I've done a quest which had some dangerous monsters involved, but that was far into the Telvanni faction quest line.