Based on my kids:
- pop to the kitchen to get a drink.
- 6mo : still roughly where you left him, might be playing. Might be a bit grumpy.
-12mo : might be sat on the table, helping himself to items in the bin. Trying to kill himself in ways you hadn't even imagined. So instead if quickly popping to get that drink/put the load of washing out, you have to take them.
- separation anxiety
6 mo: might get miffed for a few seconds when you leave the room
12mo: quickly becomes hysterical and tries to follow you. Then pulls up on your legs and clings to them so you can't walk.
- danger
6mo : can't reach the danger or does it slowly enough thst you can stop them
12mo : is attracted to danger but doesn't understand it.
- tidying up
6mo - plonk them in a corner with toys and tidy round them whilst singing etc.
12mo. They pull stuff out of cupboards for fun meaning your efforts usually generate more mess. Oh and they create more mess.
If mine us anything to go by sleep is just as bad ( for us personally it was worse at 1y), the beginning of tantrums, and there are often less naps. Oh and juggling this with return to work.
I love toddlers, they are fun and inquisitive brilliant little people. But they are far harder than 6mo and for me far far harder than newborns. The good thing is after running round after a 12mo baby 2 will probably seem easier as a new born.
As for 2 young ones - don't be afraid to put CBeebies on and learn to feed In a sling. Baby 1 you are sat on the sofa pinned down with feeding. Baby 2 (if my experience is anything to go by) you're likely feeding in the sling, whilst making lunch for your toddler, whilst doing puzzles/reading with them at the same time. It's chaotic fun.