Unfortunately you do need both devices to manually transfer your save from one device to another since Stardew saves in local (on device) files and does not currently make use of the cloud. If there's anyone at home with access to your phone, you could get them to put it to the cloud for you (in theory). Though if there's no one to do this, you may have to wait until you get home. As long as you still have the old device, it can be easily transferred once you have both in hand.
I gave an example here on how to
how to back up your stardew iOS files (copying game save files from local device to the cloud):
You can find more information on saves on the wiki here:
The game saves progress when the in-game day ends, i.e., when the farmer goes to bed, collapses from exhaustion, or collapses at 2am. All progress during a day is lost if the player quits the game without ending the day. In multiplayer, the game saves after all players click through the prompts...
stardewvalleywiki.com
And also here:
On mobile, Stardew Valley's save method is based upon the system used for computers, but with some additions to make it more suited to mobile devices.
stardewvalleywiki.com
It is fairly straight forward once you have access, good luck!
PS. Sorry to hear you're locked without your prior game's Penny.