Try primark for cheap hair accessories that look pretty, or Claire's accessories. Did you find a dress?
YouTube have so many make up tutorials, maybe practise a few times at home til you have perfected it and do your own make up on the day. Boots usually do three for two's on make up products. Or if you collect boots points, use them to buy it 
Do you have any friends/family members who can do your hair instead of giving a wedding present? If not, look at YouTube again, and practise on yourself.