Say what? The feed on sending BTC is $15 right now, so your 10 quid isn't even enough to cover fee's to spend it, say you had $20 USD, then could send a friend $5
We've been clearing 1 sat/vbyte transactions for several days now. If you are paying $15 for a transaction then you are being ripped off. A standard transaction of ~200 vbytes will cost in the region of 5-10 cents.
If you sold you would lose on the transfer, and the exchange 20% grab, you would still get zero
What exchange are you using that charges 20%? Most charge around 0.5%. Again, you are being ripped off.
I like Toshko's answer above. £10 is currently worth around 0.0004 BTC, or 40,000 sats. This is enough to make dozens of transactions. You can create multiple wallets, practice writing down seed phrases and restoring from them, practice making transactions between your wallets, notice the difference in size between legacy transactions and segwit transactions. Maybe even use half of it to buy yourself a coffee or a gift card. Enough to learn some basics and get your interest growing. Then you can decide whether or not your want to buy more.