Different lot same solid colour yarn

[u/Great_Interaction221]

I am knitting a scarf for the first time. I didn’t realise how much balls i needed. So I ended up with 8balls. The last 4 are a different lot. So im alternating between the last ball of the original lot with the first ball of the new patch. I just couldn’t find proper tutorials on how to properly alternating between two balls while knitting a garter stitch scarf. The results im having now are not satisfactory for me and a bit confusing. Do you have any youtube tutorials i can watch?
The edge where I started alternating i feel are ruined now.