EOS transactions require resources in order to complete successfully. Each account has three resources: RAM, CPU, and NET, and all three are used when sending a transaction.

RAM is a consumable resource and needs to be purchased. EOS accounts created in Edge are initially allocated 8kb of ram, which should covers a very large number of transactions.

CPU is a staked resource that recharges over several days. If you run out of CPU, just wait 1-3 days until your CPU has replenished.

NET is also a staked resource and recharges similarly to CPU. 

The initial staked amount of resources should allow you to send 10+ transactions per day for a long time. You can use third-party services to stake more EOS to your account, if necessary.