I have lumbar disk hernia for 10 years, which causes back pain and discomfort in left leg, is surgery a first option?

No. Conservative treatment is recommended first , may include pt/anti inflam med/posture & ergonomics. Other options may include medications that target the nerve, ie, gabpentin/lyrica. Epidural steroid injections can be helpful as well esp.For the leg pain. Surgery may be an option if all else fails, and in urgent situations such as progressive leg weakness and/or loss of bowel or bladder control .
No, it's not. Surgery is an option, but it is almost never the first option. Almost all physician would recommend conservative treatment, such as physical therapy and anti-inflammatories. If you have nerve entrapment symptoms, a steroid injection in your back may be beneficial. If your symptoms persist or worsen, then surgery would be an option. Good luck!
Not realy especialy. You have for ten years, the first option the conservative treatment(medications, therapy, injections) if this did not help you may think about surgery.