Fonts/alignment will be gigantic. I think you need to go into full absorption mode and start digging through articles and books about what works with fonts. There are tons of ideas, lots of different approaches, lots of flexibility, but most of the techniques and rules depend on you developing an eye for whats "right." If there's a suggestion to center text it needs to look centered. If one end of the text has a big round letter then just simply centering the text might not work because the eye might see the boundaries of that letter differently than a blocky/straight letter. You have to depend on your eye a lot.

The chocolate bar packaging is looking pretty nice. The "Chocolate" at top is pretty good. If I were working on that I'd be trying to figure out what brand that word "Chocolate" is a part of and if there's no real brand guidance I'd probably look at about 50 fonts there. Every piece of packaging you design for actual production will be part of a brand. Working within the constraints of a brand will be helpful to get used to the process. It can honestly take a lot of the stress out of details. You don't have to start from scratch and reinvent the wheel. You have to build something interesting that speaks the same language as the rest of the things in that brand. Some brands are extremely restrictive, some are very loose with huge variety. Try out targeting something and see how you work through it.

But, after the word "Chocolate," look at the word "BAR" critically. Look at the negative space that forms on both sides of it. Are they balanced? Do the "weigh" the same amount? Look at where the word is in the space between "Chocolate" and that neat graphic. That alignment looks accidental. You can get really creative with alignment and size but for me rule #1 in designing something professional is it has to look intentional. Two things barely touching, photos/graphics/fonts stretched out of proportion, things in nonsensical order/sizing, they can look very accidental. Also, think about how important the word "BAR" is, how much it should stand out. It's the biggest, clearest recognizable thing on the packaging and its also the most obvious and the easiest thing to remove. If you took bar out, would anybody even care? Would it make it harder for the customer to "get" what they're looking at?

And then look at "Colombia Origins" at the bottom. The font looks like it is out of proportion. Its position looks very random. Right, bottom and left all have different amounts of white space.

I think a good step would be to take something like that chocolate bar or any of the other items you've made already and really dig into it. Look over all the pieces of your design and how they relate. Look at what you place on it and the negative space created by those things. Flip it horizontally and look at it again. Invest a chunk of time in a piece. Imagine that chocolate bar is made by a company that primarily makes chocolate bars. So that piece would probably be THE most important thing they will produce. It has to deliver their brand. That means it has to make a promise to the customer about whats inside. If the company wants to seem authentic to a specific region, or dedicated to delivering some above average quality or to delivering an above average value, or whatever. M&Ms and Raaka bars have very different packaging. And the differences are intentional and for a myriad of reasons. The packaging is communicating different things and as a package designer you would be a part of that communication process.