What's the maximum calorie burn you have done in one session

I bought an electric cycle last month and have been cycling consistently since then.

I don't know how accurate these results are but it feels nice to see them on screen.

I've been going to the gym for a month now and this is my routine: Day 1: Chest, tricep Day 2: Back, bicep Day 3: Shoulder, abs Day 4: Bicep, Tricep Day 5: Legs

Is this a good split? Would you recommend something else?

I'm a skinny guy... Height : 5 feet 7 inches Weight : 48 kg

Can I gain weight without going to gym ??