Look at Uniswap's RouterV2 and interfact with the smart contract doing swap and adding to liquidity pool. You can do all this on testnet. Then look at how to create BEP20 for BinanceChain and see what you can do there. I've been hearing a lot about PancakeSwap. Also look at how proxy smart contract work. And then look at how to deploy a smart contract on mainnet and testnet with the same contract address. If you're not already using it, use Truffle for Smart Contract development. Once you do all of the above, please ping me and show me how they are done. 🙂