Question: how long is the unavers

We don’t actually know. The observable universe, the stuff we can see, is about 13.8 billion light years in radius based on light-travelled distance…but in the time taken to travel that distance the universe itself has expanded, so the proper distance is now around 46 billion light years radius.
This is just the universe we can see, there could be a lot more of it we can’t see because there hasn’t been time for the light to reach us.
There’s also the possibility that the universe is smaller than we think and that some of the light we see has started to bounce back to us from the edge of the universe presenting us with images of the same structures, just at different ages.
The best estmates for the current size of the universe range from around 45 billion light years radius up to around 1.5 x 10^34 light years, with the bit we see being an insignificant fraction of the whole (in which case I hope it’s a representative fraction, not some distant outlier in the distribution, or we’ve been mistakenly wasting our time trying to explain the whole on the basis of some random edge-case weirdness).