What cage do you recommend for one or two parakeets?

As big as you can fit, they love to fly around the cage and will need plenty of toys to keep them happy. A solitary budgie can have a fairly small cage.

A single budgie I would put in something like this https://www.petstock.com.au/products/111...

My 2 budgies have a cage 80cm high with 80cm length and about 40cm width.

The cage for 2 budgies needs to be fairly large so they have room to fly a bit as well as move away from each other when they want some space.

One is better if you have plenty of time to spend with the bird. A single bird will develop a bond to you and become a great friend.

A pair of budgies can become close to you but they will also bond to one another and want to spend most of their time with one another. Budgie pairs make beautiful chirping sounds when they chatter to one another and it's good to have two if you don't have the time to spend with them.

Boys and girls are both loving, boys are apparently more loving but it all depend on the specific birds personality. If you tame the bird from a young age, it doesn't matter the gender, either will be cuddly.

Yeah they poop pretty much everywhere. I always end up with poop all over my shoulder and the back of my chair. But the poops are small and easy to clean off. I always keep tissues on hand to wipe them off.

I recommend the biggest cage you can get. Petco has 30x16x16 inch finch cages that work good for budgies.

Having one or two depends on what you want. Usually when you have one bird, and it is tame, it will bond with you. But when you have two they bond with each other instead. But if the birds are tame, they can both love you too and play with you.

Boys are said to be more loving. But it also depends on if the bird is tame or not.

Birds will poop where ever. They dont have bathrooms. My budgies usually dont poop while flying, but sometimes i see their poop on my wall lol.