Thanks! So sorry, last question; can I earn more skills throughout the game?
When you reach level 4, there are several interchangeable options to choose from. One is increasing ability scores, which we've already discussed. The other is taking somethings thats called 'A Feat' in DnD. It is some trait that changes something about your character and they are very diverse. There is one feat in particular that is called 'Skilled' which allows you to take 3 extra skills from the pool of all existing skills in the game.
Neprostoman is right.
If I were you, I would either take a background that gives you proficiency in desired skills OR one that makes sense for what you think Bilbo is. None fit Bilbo perfectly, but you can think about it a bit. For example, Bilbo starts the Hobbit as a Hermit, but the Hermit background doesn't give any of the recommended proficiency. If you choose a background based on what makes sense for Bilbo, I would take the skilled feat later to make up the skills. If you choose a background based on skills (and make sure none of your granted skills overlap), I would take a feat that boosts your abilities in dexterity-based activities, maybe boosting your dexterity score.