-Digimushrooms are common items lying on the ground in Native Forest, which is a good substitute if you a low on meat
Recruit Digimon
-Agumon, Palmon, Kunemon, Coelamon, Etemon
Agumon
Agumon charges at you as soon as you enter the Native Forest. He isn't a particularly strong boss Digimon. Even if you haven't trained at the Green Gym yet he should be an easy win. When you defeat him he regains his memory of the city and decides to come help you.
Agumon is the owner of the Item Bank in File City. As soon as you defeat him he will turn the abandoned shop next to Jijimons house into his bank. You can deposit items in the bank free of charge so you have more room in your bag early on in the game.
Palmon
Palmon can be found one screen down from the Native Forest toilet screen. She is staring off into the woods fantasizing about being a beautiful flower. After repeatedly annoying her by talking with her, she will battle you. Her defense isn't all that great, but she has a few attacks that might dish out over 300 damage so have some small recoveries handy.
After you defeat her she will drop a brain chip. Apparently after battling you she regains the memory that she hates fighting. Upon regaining her memory she joins the city as the new meat farmer upgrading the farm to giant meats instead of the regular meats. An added bonus is that if you want to buy some extra giant meat she will sell you them for 500 bits a piece.
Kunemon
Kunemon has a special area in Native Forest named Kunemon's Bed. This screen can be found one screen to the right of the Native Forest toilet screen. He can be found looking for food in a tree. If you talk to him he will ask you for food, and if you give it to him he will eat it and then battle you. Kunemon is probably one of the toughest Digimon early on in the Native Forest. He has decent defense and attacks. Have a powerful Digimon or keep some small recoveries on hand when you face him.
Kunemon will drop a MP Chip after you defeat him. He then decides that he wants to help you in the city. When you go back to the city you find that he has eaten through a patch in the southern screen of File City. This is a pretty useful shortcut to get from File City to the Digimon Bridge quickly.
Coelamon
Coela Point is located two screens down from the eastern end of Kunemon's bed and rumor has it there is a Digimon that shows up in the late afternoon near Coela Point each day. Visit Coela Point during the late afternoon and you should see a dark shadow swimming in the water. Walk up to the shadow and Coelamon should pop out and greet you. Answer his question by saying you looked everywhere for him and he should let you on his back so you can get to the other side.
Head back to the bridge area and you will notice the bridge is fixed. Visit Coelamon again and he will say he has no purpose now that the bridge is fixed. He says he wants to come to the city and help you out. After he joins the city he opens up a small item shop that sells small recoveries, MP recoveries, and regular meats. All of these are essential to you at the early point in the game.