Hello i want to learn about bitcoins and i have a budget of 300$ USD i know i can’t mine bitcoins with this little amount so i would like to know the hardware and the altcoin which i can mine and then exchange to btc
You might be able to pick up an AMD R9 RX-480 graphics card for that, if they’re in stock. These are really great cards for mining. You can use it to mine Ethereum (Classic), Zcash, Monero, and so on, in their current order of profitability.
To see which coins are most profitable to mine, go to this site:
Note that some algos for which ASICs are available, such as SHA-256, Scrypt and X11, are not profitable to mine with a GPU. You want to consider only those coins with an ASIC-resistant algo. Research the various algos to discover which those are.