Hello movexz,
Depending on how much you want to walk and how much time you have I would take a taxi from the train station to either Porto Nuova (the Roman Gate to the old Town) or to Piazza San Zeno. San Zeno is slightly further way but will give you a broader look at the city.
From San Zeno check out the Basilica di San Zeno Maggiore which interesting and the wander the San Zeno neighborhood to the edge of the river and follow that around to Castelvecchio and take the pedestrian bridge Ponte Scaligero out over the river. From there take via Roma to Piazza Bra and join up with the Porto Nuova walk.
The Roman Arena dominates Piazza Bra and is a great place to wander. From there just keep following the city through to the loverly Piazza delle Erbe - lively with booths of food and the usual tourist stuff - and on towards Ponte Pietra. Cross the historic bridge - the white water under the bridge is the remnants of the old bridge bombed in WWII - and walk up towards the Funicolare di Castel San Pietro to reach the castle. That will give you views of the city and curve in the river.
If you really want my advice though what I would do is not go to the castle but instead turn right and go to the Teatro Romano and tour the excellent Museo Archeologico al Teatro Romano. It is the old Roman Theater (still used) the Archeological Museum - Roman and pre-Roman - along with an old convent attached to the site. If you walk all the way up the views are virtually the same as those from the castle but I find the ruins and museum much more interesting.
Don't sweat where you're going too much just wander the city and it will lead you to the various piazzas anyway. There was a famous photography museum that was in the Roman ruins but last I heard it had not reopened post lockdown. I'm hoping it will be open again when I visit in October.
Verona is super charming - have a great visit,
=Tod