In my opinion, using gain automation to even out levels should be your first step. It's completely transparent and non-destructive. And it'll do a better job controlling levels than a compressor ever could because the process is manual. It only takes maybe 15 minutes to apply to an entire lead vocal and is the single biggest game-changer possible. That's not to say you shouldn't use a compressor. Compressors add an additional layer of control and impart cool tonal characteristics. I frequently use gain automation, compression, and a limiter.
Saw this from a professor of mine. He looked at my vocal track and said "bypass everything, automate the gain or just cut the clips and adjust the gain to properly even out the track. The compressor won't have to work as hard and you can use it not to fix but to give color". Made the tracks sound soooooo much more natural and less processed when I did that
