There's lots you can do with that combo but as you're new I'll steer away from the whole grains for now (despite the fact you have enough for a 20lt brew with them alone) and look at your malt extracts & hops.
You could try something super simple like this...
Cascading Pale Ale
Batch size: 23lts
Boil time: 60 min
Est.IBUs: 29.5
Est. ABV: 4.4% (after bottling)
OG: 1.043
FG: 1.011
1kg of Light Dry Malt Extract
2kg of Ultralight Liquid malt Extract
73g of cascade hops
- 18g @ 60min
- 20g @ 20min
- 20g @10min
- 15g @ 0min (flameout)
1 x packet of US-05 Yeast
Firstly, clean and sanitize all your gear. This means your Coopers DIY fermenter including the tap, collar and lid, any stirring paddles (or large spoons) you might use in mixing it and anything else you might need. Your DIY kit should have come with some sanitizing agent.
Dissolve 500g of the Light Dry Malt into 5 liters of boiling water in a large pot and bring to a roiling boil on the stovetop for 5 minutes. Then add 18g of the hops and boil for a further 40 minutes. Add 20g of the hops and boil for another 10 minutes. Add 20g of hops and boil for another 10 minutes then add the last 15g of hops and take the pot off of the heat.
Dissolve the the remaining 500g of Light dry malt and the 2kg of Ultralight Liquid malt extract into the pot and pour the entire hot sticky contents of the pot into your sanitized fermenter. Now top this up to 23 liters with cool clean water from the kitchen tap (please don't use the garden hose, despite how convenient it might appear) and pop your lid on. Now you just need to wait for the temp to drop to between 18 - 20'c
Once the temperature is there, sanitize your largest plastic or metal serving spoon, some scissors and even the outside of the yeast packet (if it seems waterproof, most are). Use the spoon to give the contents of the fermenter a good vigorous mixing. This introduces oxygen to the sweet sticky liquid (wort) but be careful not to touch the insides of the fermenter or any of the wort with your bare hands as this can introduce an infection to you beer.
Then cut open the packet, open your fermenter and sprinkle the contents evenly over the top of the wort within then seal her back up. Congrats, in 3 - 4 weeks you'll have beer and can bottle it.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
This should produce a pleasantly hoppy, moderately bitter Australian Style Pale Ale.
A few tips I wish people had given me when I started:
- Sanitize the crap out of everything especially when you are beginning you can't be too careful. If it comes in contact with your beer, directly or indirectly, it should be clean and sanitized. I even sanitize the can opener I use to open my liquid malt tins.
- Your hands are filthy - in fact all of you is filthy in general. It doesn't matter how good your hygiene is, your body constantly carries thousands on bacteria that will infect and ruin your beer given the chance. So wash your hands and try to keep them out of the beer.
- Temperature control is everything. The yeast producing your alcohol releases different flavours at different temperatures. With US-05 you want to keep your yeast around 18'c to avoid any off-tasting flavours.
- Use a hydrometer. Take a reading (from the tap) before adding the yeast (write this down somewhere) and check it again after a week or so. Once the reading has been stable for two or three days, your yeast is done. These numbers let you know how your yeast is doing and how strong your final beer actually is.
- Take notes, lots of notes. You might make a mistake you'll want to avoid in future or make a great beer you'll want to reproduce again. Notes help out here.
I hope this has helped, sorry about the metric measures but it's what I use.