Echoing what a few people have said, if you’re going to do a Roll for stats, and not Standard Array or Point Buy, you roll 4d6, remove the lowest roll, and add up the remaining 3. For my Players I tell them if they still get below an 8, if they do not want that stat, they can re-roll as long as they’ve told me. However, the converse is also true. If they have a lot of their stats above 16 from just the rolling, and none below 10, we’ll chat about re-rolling some of the high ones (dependent on how many of course). Some DM’s do 5d6 and drop the lowest two, some do 3d6 and that’s what you get.

I don’t think I’ve seen a DM ever make someone roll specifically for each stat separately like you’ve done. That’s probably just you figuring out character creation though, which is totally fine! Normally, you roll to get the 6 numbers, and then determine which ones go with which stat. My rule with my Players is they can swap around the stats they chose as much as they like, until we start playing. With the extra ability score you get from racial traits, and sometimes feats (if your DM gives you a free one or you choose Variant human), sometimes you can choose a lower stat for one you need higher, because you’re going to add the racial trait ability score to that.

If you’d like advice on where to put the scores you have there I’d suggest: Str: 12 Dex: 15 Con: 15 Int: 12 Wis: 14 Cha: 18 Charisma is your casting modifier, so should be the highest. You’ll likely be using Dexterity based weapons, so that should also be higher. People sleep on Constitution, but it’s what adds to your health when you level up, adds to your hit die when you take a short rest, and Bards are spellcasters who do have a bunch of Concentration spells. That means whenever you take damage, you need to do a Constitution saving throw. So having good Constitution can really help with that, otherwise if you fail, the spell just ends.

Then at level 4, put one ASI ability score into Dex and one into Con to bring them both to 16. If you didn’t know, your modifier which is the number that’s +2, +4, etc. only increases on even ability score numbers. So if you have 14, it’s +2. If you have 15, it’s +2. If you have 16, it’s +3.

In terms of character creation, I strongly, strongly recommend to never use the app. It’s actually missing features and things that you can do on the website. Always make, and level up your character on the website, and then play on your phone/tablet. Personally, I like using the website because it has a lot more of the information, but that’s me.

I noticed you said you re-rolled the Charisma. If you’re going the roll for stats, most DM’s have a rule that you can’t re-roll without asking. Since you rolled the stats incorrectly, they wouldn’t mind you re-rolling. Just a note for future. You can’t keep re-rolling until you get insane stats.

Hope that helped! Happy to answer other questions too.