I've used bike seats when the lad and the lass were smaller, and a trail-a-bike when the lass was bigger (the lad went straight to riding himself).
Loading up is not an issue. You lean your bike against something solid as you normally would. Loading the wriggling monster is just like handling a toddler in any situation - you soon learn what works for you and your child. It is easier if you've got someone to support the bike but without that, you soon work out what works for you.
I would NOT use a kick stand, they are just implements for dumping your bike on the ground.
After the first couple of trips, you'll remember this thread and wonder why you asked.
To be honest, once the child is loaded and ready to go, the biggest hassle is swinging your leg over the saddle without kicking them in the face.