just look over your plants when you water them. If you see bugs or fungus, then spray them. If you don't see any problems then don't worry, they are fine! If the spray doesn't seem to be helping the problem, then try to research what the problem is first...internet searches with pics are often very helpful....and then what will usually solve that problem.
with my berries, the birds like to come eat them just as soon as they begin to ripen. I had to put a nylon stocking over the ripening berry branches to keep the birds from harvesting for me.
I don't like to use sprays if I dont absolutely have to, I would rather pick off bugs I see and feed them to my chickens. This did not work out on the war with the snails and I did finally have to use snail bait pellets. That did the trick....and weeding along fence lines where the snails liked to hide was a huge improvement on the snail war.

We have little lizards and sometimes toads that live in the garden and eat thier weight in bugs. I leave a jar lid full of water out for them to encourage them to stay and help with bug control.
good luck with your new berry bushes, and dont worry so much,...just keep looking for signs of trouble and you will be fine.