As an LVN here in CA, LA area, I can say that it was the toughest thing I've ever gone through. It took me a little over 24 months of schooling plus an extra time for boards, and licensure waiting. I was working FT as a CNA too. Study time depends on you, and it's relative, meaning what works for you may or may not work for others.
On school days, school was 8A-2p, I'd get home by 3P, relax, unwind, and eat, and start studying by 5p. I'd study until bedtime, usually 9P or 10P, with a couple half-hour breaks to digest what i was reading. If it was a long lecture or a tough one, I'd probably study until I feel asleep. LOL no joke i woke up one morning with my face planted on my textbook. READ, READ, READ is my advice. LVN school was tough, and my life really revolved around work and school with little time to mess around.
LVNs at least here in CA are phased out of acute-care settings, with exception of small-community based hospitals still utilizing LVNs. Most hospitals are leaning toward the coveted "Magnet Status", and even RNs without BSNs are being forced to go back to school.
One step at a time.you'll get there. Best of luck in your nursing career.