I am married to an excellent amateur violinist
We play together often. A lot of what we play is actually violin/orchestra music, but when you buy the violin part it usually comes with a piano reduction of the orchestra score. You'd certainly be able to handle those piano parts, maybe even sight-read large portions, and since it's an orchestral reduction you can just leave out notes you don't feel like playing! I don't really have a grasp of difficulty level for violin, but when we started playing together (ages 14/15) we played Vivaldi "Spring" and Mozart concerto no. 5. For violin, I do know that "concerto" doesn't necessarily mean "difficult" the way that it does for piano: the Bach double violin concerto, for example, is accessible to intermediate violin students. More recently we've played a Vivaldi concerto in G minor (can't remember the number, sorry), Dvorak Romance in F minor, and Saint-Saens Introduction and Rondo Capriccioso, which took a lot of work for my wife so maybe that's more in the advanced category? And Vivaldi "Summer" which came together much more quickly... and we're actually going out to perform it tonight. We've been wanting to look at the Beethoven violin sonatas but haven't got around to it yet.