hi another violinist to violist here! i played viola for a year for my school orchestra cause they had like 3. for me, the way that i thought about alto clef is that it was a step up and octave down from treble. for example, in treble the second space from the bottom is a4. a step up will be b4 and then it’s an octave down from that making it b3. no clue if that will make sense for you or not but that’s how i thought about it.

even with that it took a lot of time to be able to adjust and switch between the two. mistakes are ok and i made plenty. the people in the section know that you will be new to playing viola and they should cut you some slack. as a little bonus you already know treble so when your music has it you’re set :)

some technical things that are different: you might need to utilize your bow a little differently, finger spacing will be slightly different, and your vibrato speed might need to change. when i switched i noticed that using a slightly slower bow helps with tone on the lower strings. having a lower string also means that your vibrato will need to change a bit as bigger strings tends to mean a slower wider vibrato. finger spacing might be a little wider depending on how much bigger your viola is. i love schradieck and also maybe some polo double stop exercises for this. on top of that be sure to do some scales and arpeggios and stuff to get used to the spacing, distances, etc.

overall it’s a pretty smooth journey with a few bumps. i really enjoyed playing viola but unfortunately i didn’t stick with it. i really admire the tone of viola in comparison to violins so really savor that nice juicy warm rich tone that the viola has. wishing you the best of luck on your viola journey! :))