Okay, I've been working on a story kind of like this recently, and I understand these concerns. ^^; It's hard to figure out how to keep things interesting in a grounded story (as in, most of the conflicts are interpersonal) when all the characters are relatively kind and nice. A lot of potential conflicts just wouldn't happen, and another large portion would be resolved quickly because the characters don't want to see each other hurt.
So how do you get to that portion of conflicts that would take time and effort to resolve despite the characters' kindness? The answer is actually very simple: character flaws, and lots of them. ^^
To give an example, here's a brief rundown of my characters' troublemaking flaws. To reiterate, they're all very nice people. However:
A: Immature, socially anxious, conflict-avoidant; tends to blame himself for things.
B: Poor impulse control; prone to jealousy and sensitive about proving his worth-- despite this, he often tries (semi-successfully...) to hide and repress negative emotions.
C: Stubborn and willful; can hold a grudge for years. ^^; When faced with someone who's not quite so nice, he's more likely to choose violence than tolerance.
D: Brutally honest, sometimes to the point of dismissing people's feelings. Likes to tease. Finds it difficult to share her personal problems with others.
E: The all-time champion of emotional repression, causing rifts between herself and others that they often can't detect until it's too late. Struggles with imposter syndrome.
F: Between his upbringing, trauma, and neurodivergence, has very little in the way of social skills, and has made a habit of hiding things in order to seem normal. Very shy at an age (53) where it is no longer socially acceptable to be shy. ^^; Also tends to blame himself for things.
...So yeah, there's a lot to work with there. :9 At one point or another, one person's flaw will have to have a particularly unfortunate interaction with another person's flaw (e.g. D's insensitivity paired with B's hyper-sensitivity, or A's social anxiety paired with F's social ineptitude)
And to make things even more fun, another strategy I like to use (one I think most slice-of-life writers use) is to structure the story with events and activities. Keep the characters working on things, going places, and solving problems together, and you'll have more opportunities to create and explore conflict.
One last hint: don't be afraid to give your characters some backbone. ^^ As ideal as it might seem for friends having problems to both immediately capitulate and try to find another way forward, it's not really realistic. Most people tend to think that their ideas about things are correct-- that's why they have them and feel comfortable expressing them. :T And most of the time they have to be convinced to drop them for someone else's.
Or y'know, they might have wildly different ideas about how to fix their problem, and end up creating a second layer of conflict to resolve. ^^; Let it happen; let things get a little crazy. Let them struggle with each other and communicate unsuccessfully before reaching a true understanding.