Hi! I can't seem to connect two blocks in my series - the blocks already excist, and I want to connect. But how?

@user1347​ Just from the picture alone, it's hard to solve your problem. Are you receiving an error message if you try to connect them? Or are you asking how to connect two blocks that already exist in general?

For the latter, if you hover over a block, an arrow should appear next to the block. You click and drag that arrow to connect two blocks.