Help with my PvT

Hello im coming back to starcraft after some years of not playing. I made it from bronze to gold 3 and I am having alot of fun. I had to learn about builds and macroing and microing and it been alot. Now I ran into alot of problems playing against terran. To me the seem so strong with widow mines in my min lines or alot of reapers early game or the mass marine, marauders, tanks, and medivacs. What is a good build that can help counter alot of this? Someone did tell me to scout with a probe, but Idk what I am looking for. I see them make 1-3 barracks, factory, starport, but they all seem to do that. So what am I looking for?

Switch to Terran, they are unbeatable.