How to decide on whether should I buy or sell Call or Put options?

Your decision to buy/sell call or put options should depend on your market outlook. If you think the market will do well this month, you should consider a "BUY call option" or "SELL put option". If you think the market will fall this month, then a 'SELL call option' and a 'BUY put option' would be the right move.

In addition to personal research, traders should also keep an eye on current events, the announcement of financial results, major budget or war news, etc., as these can serve as an important factor in determining a stock trend.