I would not normalize either track before mixing. If you max out one track, then you have no headroom for further processing. Once you get a final mix, then you may adjust the final stereo track if it isn't hot enough (that's mastering).

One tip I use to mix is to listen at a very low volume. If I can hear all the instruments, it will be good when louder. I also listen from down the hall. I also test the mix on lots of players, from good stereo systems to boomboxes to headphones to earbuds to cars etc.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.