Funnily enough i was going to download a picture of the 2nd one myself to find out what it was called because my brother has it growing in his garden.
It has deep yellow flowers like daisies

First one is some kind of Mallow, but which one?
Second is Ragweed, I think. Certainly is is one of the things you get from wild bird seed.

The first one is Malva moschata alba the second is Jacobaea vulgaris (AKA Ragwort), a very common, but potentially highly toxic weed which you should not allow to set seed in your garden:

http://www.ragwortfacts.com

Ragwort is one of only five plants named as an injurious weed under the provisions of the Weeds Act 1959. Under the terms of this act, a land occupier can be required by the Secretary of State for Environment, Food and Rural Affairs to prevent the spread of the plant.

Thanks for the info, The ragwort be pulled up tomorrow. Am I ok to put it on my compost heap?

Pdb,

Yes, it will be fine on your compost since it isn't anywhere close to setting seed yet.