There isn't much of a difference between the BUSD and the USDT.
There is a difference of night and day from the technical point of view but from a trader's point of view, yeah there's not much separating them. Both have a stable value and are good for the management of portfolios.
Tether (USDT) has a higher volume hence more liquidity in terms of price while BUSD is still far behind.
If you're a novice trader, you should focus on volume, arbitrage chances, and so on.
I don't think novice traders should ever focus on things like arbitrage because arbitrage trading requires superior knowledge and understanding of the market.