the car is likely stuck in second as that is the default gear when there is a transmission issue.
Is the check engine light on? I suspect it is.
Have you checked for transmission codes? if so what are they?
There are several things that go wrong with these that are fairly simple to fix and cheaper than the solenoid.
To replace the solenoid pack (by the way I have never had this fix a transmission problem) you are going to remove just about everything on the drivers front of the engine compartment. The air filter housing, computers, battery, fuse boxes, etc. Then you will be ably to see the solenoid pack located on the front of the transmission. You will then need to remove the cooler lines and the input speed sensor from the transmission. The three bolts for the solenoid pack can be removed with a 10mm socket. A new solenoid pack can be purchased from the dealer. I’m happy to assist further over the phone at
https://www.6ya.com/expert/jeremy_d728a59f986299fa