Veterinarian side gigs

I am currently a relief veterinarian working through a company that schedules my shifts, and I do receive a W-2 through them. I also work vaccine clinics separately from this and receive 1099s. Can I claim mileage for my W-2 job or only for the 1099 jobs? Also, I attend veterinary conferences in order to fulfill my continuing education  credits to uphold my license. Can I deduct the conference expenses (i.e. flights, registration fees, transit, food, etc) from my 1099s as an independent contractor? Thanks!