The Roku 1 uses an IR remote, so a replacement isn't that expensive. In fact, you can probably go into a local store that sells generic remotes and find one that list support for Roku devices for about $10 or so. But first, make sure your remote batteries are good, and inserted correctly. Different Roku remotes have different battery orientation.
But since the Roku 1 is WiFi only, you have to connect it to the wireless before you can use a phone app. There's no other way to connect it to a network without a remote. Unless you know the WiFi SSID and password of the last network that it connected to, and change your WiFi to match. In that case it should auto-reconnect.
Dan
Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.