The London session coincides with the Nigerian time zone (8AM-12PM).
1. If you actively trade any of these major currency pair, EUR/USD, GBP/USD, EUR/GBP or USD/CHF, then you can trade London session.
Most activity on EUR/USD or EUR/GBP is during the Frankfurt & London opens. So, most of the trading will be done between 8AM to 10:30AM. If you are trading after that time, it is generally low edge setups (atleast that's the case for me).
2. But if you trade other currency pairs like USD/JPY or any JPY pairs, then it is mostly active during Asian & NY session. During London, GBP/JPY does move, but I've not traded it actively.
3. If you trade DAX, then also 8AM to 12PM.
4. If you trade NAS100 or US30, then you will need to trade during NY session. It is most active after 3PM. But you can still see volatility from 1PM Nigeria time.
The spreads also for these instruments are lowest during these active sessions. So, the answer depends on what you trade.
I'll add, first learn about the instrument you want to trade (know why you want to trade it, what is your reason), what time does it move, do you have a strategy to trade it? Does your strategy have any edge on that instrument?