You can definitely gain aerobic (cardio) conditioning from resistance training alone.
That's all I did when I competed at a high level in obstacle course races from 2011-2017. I performed ZERO running or traditional cardio in my training and still finished in the top 3 of my age group (over several age groups from 36-42). All of my training was resistance based (kettlebells, bodyweight, sandbags, med balls, bands, etc.).
Looking back, I realized I was performing High Intensity Repeat Training (HIRT) and A+A before I knew what they were along with strength/hypertrophy training using full-body circuits 90% of the time (supersets made up the other 10%) using timed sets (30/30, 20/40, 15/45, 40/20, etc.) or Every Minute On The Minute (EMOTM) or other similar methods.
However, that may not work for you.
There are two options when performing resistance training and cardio on the same day:
1.) Train them at different times at least 4-6 hours apart (preferably 6-8 hours).
2.) Perform cardio after resistance training.
Otherwise, it's ideal to train them on separate days.
As for stretching, dynamic before a workout is fine. Otherwise, save the static stretching for post-workout (or off days).