A little tougher to cover panfish to walleyes where you want 4lb test one day and 8lb the next. Two recommendations:
1) String up with 10-15 pound braid of your choice and tie on a 4-6-8 lb leader depending on how you’re fishing any given day. Most versatile option but you have to buy two lines and learn to tie a line-to-line knot if you don’t know how to already.
2) Spool up with one all-round line. My bias is towards tougher lines with less stretch and are more manageable than fluorocarbon (assuming you’re using spinning). The lines I’d use would be Yo-Zuri Hybrid 6lb or Sufix Advance Mono also 6lb. Note these are thicker lines and the equivalent to most 8lb mono/fluoro so you could consider going down in test too (4 lb sounds light but is pretty strong line in those brands if I were mostly fishing pannies).