Looking up every piece separately to buy on Bricklink will take some time. If you are looking for a lot of pieces you probably won’t find all the pieces in one store. Create a Wanted List will make things easier.
Going back to the 1×1 brick can see My Wanted List has a (2) after it. That means it is on my wanted list. Below that is Add to My Wanted List. I can add this piece to an existing or new wanted list.
Clicking on Add to My Wanted List brings up this screen. I can select the quantity, color, and condition. I can set a max price and choose if I want to be notified when someone adds this piece to their store. Except for some rare pieces, I have the notifications turned off otherwise you will get emails all day long. On the left is the names of my wanted lists so you can have a list by project or use the Default Wanted List. Now go find a store to fill your lists. I found the store Recycled Brick. Of course.
Once in a store go to the Shop tab and below is Wanted List. It will show everything in that store that is on your lists. On the left is a list of all the wanted lists. You can select and deselect which ones you want to see which pieces are available. You can add the ones that you want to the cart and checkout.
Along the top of the page on the right you will see a heart with a Want under it. This is a quick way to get to your wanted lists. Click there will take you to a new screen.
Here you can see the list of your wanted lists and an Easy Buy option. You can use this to find stores that have the most pieces to fill that list. My default list has 10 items in it. When I click Easy Buy it will search to find the least amount of stores to complete that list. There may be no stores that have all the pieces so it could make multiple carts
Here it is finding the stores that can fulfill the list. It will give you a list from this screen and below it is a button that says Create Carts. Once you do that it will make shopping carts in the stores that have those pieces. Or you can from the Wanted List page use the Auto-Select button.
After creating the cart you will go here. All your active store carts will be here. You can select View Cart.
Now you can hit Proceed to Checkout. With Easy Buy, you can’t deselect international stores. It looks at price and shipping costs and supposedly gives you the best price. I don’t know if it does. In my example I made a cart that had all the pieces in my store. You probably won’t find everything in one store. I usually find the store that has the rarest or most unique piece on my wanted list and then see how much that store has on the wanted list from within the store. Easy Buy is easy but I don’t want to buy 10 pieces from 10 different stores.