Once you get into the swing of it it's not so bad, ds has been severely cmp allergic since weaning at 6 months so I've lots of experience (although he's nearly 4 now so I'm trying to remember how I did it!). He has multiple allergies unfortunately so hopefully you will have more choice than we did.
The first rule is never assume milk isn't in something - always label read. Crisps, bread, crackers, salami, frankfurters basically all sorts of things that you may not be aware of.
Toast, pita bread, Jacobs Cream Crackers (believe it or not - no cream!), some oatcakes, breadsticks. M&S ciabatta is fine, I slice it and brush with garlic olive oil to make garlic bread (although your dd might be a little young for that). Fruit/veg/raisins/meat. Mine still live on Goodies apple rice cakes. You can make a white sauce with Oat/rice milk and Pure spread the usual way. Fishfingers are usually fine.
Eating out is a bit of a problem but we go to Pizza Express and order pizza with no cheese and it's always been fine. Always stress that there is an allergy problem though so they don't cut pizza with a knife used before. Wagamamas is good, Japaneses/Chinese don't tend to use dairy anyway. If you're going for baby led weaning you could stiry fry udon noodles with chicken/sweetcorn etc.
Some of the Hipp jars are fine to use as well, spag bol was ds's favourite. Also the Goodies range has lots that's ok, gingerbread men, snack bars etc.
Sorry if it's been a long ramble but you'll soon work it all out and get used to it. Just make sure you always carry snacks with you to make life easier. Good luck