Congrats you are thinking about it at the right time
Depending on the size of yiur state, to run for Senate you need to raise at least a million bucks
Maybe a little less if it is small or North Dakota or Alaska
You need to have that much to do all the stuff, but more importantly you need to show potential supporters you are the the real deal, and raising cash is a huge part of that kind of seat
There is much more to it, esp messaging, but for first time candidates the money is what usually trips them up