New caravan issues

We are new to caravanning and have just bought a beautiful lunar Venus 6 birth. We had pitched it for 8 weeks in harrogate- having missed a weekend we arrived this week and noticed all the windows were heavily condensed around the wondow seals- is this normal? Is there anything we can do to reduce it?

also I think we have a blockage in the waste system as I opened the shower door which we have never used to the most vile smell and what looked like vomit- must have come up thought the plug hole?!!

would appreciate any advice

thanks