Try loads of different demo accounts. Some companies range in spreads dramatically and depending on your strategy/ style can be the difference between a blown account and getting some pips in the bag.
I trade with ICMarkets on the ctrader platform (demo). I really like it, tried a few brokers with MT4 and MT5 but I personally feel more comfortable with the ctrader platform.
It’s a personal choice so try out as many as you can and find out what you like.
Also, other brokers use ctrader, not just ICMarkets.
All the best.