I did some research on Bitcoin transaction but I wasn't too clear on some things.
Bitcoin transaction fees are the rewards miners get when they verify transactions therefore the bigger the transaction fees the more inclined miners would be to verify the block.Does this mean that if two Bitcoin transactions are carried out simultaneously, the transaction with larger block chargess would likely be validated before that of lower transaction fees?
Take note that validation is for nodes, while confirmation of tx's is for the miners. Miners can choose to include any tx in their block that they are trying to mine, but they are incentivized to first include tx's that pay the higher fees because it earns them more rewards should they find the block. That's why it is recommended to check
https://mempool.space/ before making your tx, so you choose a suitable fee. I don't know if i've answered your question, so i'll like to add this; tx's aren't mined individually, but in blocks that can contain over 2000 tx's, and once a block is found, all tx's in it becomes comfirmed, now take note that all the tx's wouldn't have exactly the same fees attached to them, but fees that the miner considers suitable irrespective of when the tx was made.
Also aside from network congestion which can be avoided by transacting when the network is less populated and transaction size , how does block space demand affect transaction fees?
The address that you use affects the tx fees as well, SegWit transactions for example are cheaper.
I will definitely do some research about memepool and I will also read on segwit transactions so I can understand this transaction process properly