>>12753032it depends on what you like. “modeling” is too vague.
if you want to be an academic physicist, then the best thing you can do as an undergrad is to hook up with researchers in a field you have a passion for. so you should ask your professors about research opportunities with them or with groups beyond your particular school. the best leg up to grad school is having good research experience beforehand. and the best leg up for your future beyond grad school is having done important research quickly while still a grad student.
OTOH if you are not all-in on that very challenging career path (since it pays you shit anyway even if you are fucking einstein) then you can enrich your life a lot more by not specializing so early. undergrad is the one time in your life you have the opportunity to pursue whatever plethora of interests you have. which might be great in life. but nowadays being a successful physicist requires a lot of specialization and you need to start specializing even in undergrad to really succeed
