This is something I've been working on for some time. I really like fruit/candy/sweet/fizzy mixes and have spent the last few weeks working on some.
Flavorah Lemonade is a great flavour, worth giving a go. I'm impressed with flavorah atm. I've recently ordered a lot of their flavours and will be playing with them early next week when I have some time off work.
I recently posted a FRUITGASM clone which you might like - it's candy like, but not sour. I also recently did a really simple pink lemonade which is good. Also check out my yoda snot clone which is a lemon/lime. Check these out, I think they may be in the direction you are looking for.
Tbh, I've found a majority of the DIY community seem to go for creamy/desert/cake/custard type mixes. There has been some great stuff posted but I always lean more towards sweet/sour/candy/fizzy vapes. I've not found a great deal online so far that quite satisfies me which is why I'm spending so much time trying to work it out. I'm a way off yet but making progress.
Where about in the world are you? There is a line of flavouring called Kandi-hed that does a lot of candy type flavours. They are based in the UK. I haven't had a great deal of use out of them so far but they are along the lines of what I think you're looking for. You may have better results than me.
DV Lemon Sherbet is also quite effective. As others have said, TPA Citrus Punch is great for adding fizz/carbonation, however, I've found the flavour to not be very versatile so it can be hard to work with. TPA champagne is quite effective in doing the same thing at 0.5-1.5%. It will add fizz/carbonation and a bit of bitterness but won't have have as much effect on the other flavours as TPA Citrus punch.
A lot of guys here are likely to recommend FA for fruit. I love FA but had found they are too natural tasting for successful candy type vapes. Again, there have been some great recipes using this company but in my experience they are better for the natural tasting stuff. A lot of their flavours take a lot of work to 'tame' into a more artificial candy type taste - and are therefore not very versatile when mixing with a candy taste in mind. However, FA Citrus mix is a great flavour for adding a complex, citrus aspects to a mix - 0.5-2.5%.
Hope that helps in some way. I'll keep an eye to anything you post as it seems you are looking for a similar type of vape to me