How are we dealing with the screaming and crying?

It seems in the last week or so my son has started having 'proper' tantrums. He will screech and then burst into tears over the tiniest thing. Its starting to get me a bit worried I'm not coping as well as I thought I would when this stage inevitably crept up on us. Today I gave my son a packet of crisps whilst we were in the supermarket and he proceeded to tip the packet upside down and spill them everywhere. I know he hasn't done this on purpose, I'm not mad or upset, I just try to tidy them as best I can. He starts screaming at the top of his lungs because I'm not giving them back to him, but I didn't want to give him crisps that had been in the supermarket floor. I didn't have any back up snacks and I was headed to the checkouts so I just persevered and tried distracting him by letting him hold things from the trolley until we got to the car. It's just so disheartening, I had an old lady come over to us when I was cleaning the crisps off the floor and give my son a look like "oh you better listen to your mummy" which she might have thought was helpful, but it wasn't. It just made him shy and try to bury into me when I'm trying to clean without being the way and it was overwhelming. He has a few mini tantrums a day, mostly if I'm not preparing food fast enough. I just try to talk calmly to him and explain what's happened, and let him have his moment and try to co-regulate or whatever the term is. We have a cuddle and I'll try to distract him with a toy or anything within reach tbh. It seems to work well at the moment but I don't know how else I'm supposed to deal with it, or if anyone has any tips?