From my understanding staking is used to get resources?
And if so, how much does one need to stake a decent amount?
And which mobile wallet do you need to stake and do you need to have the app running all the time?
Each account has some amount of EOS. Part of that EOS can be staked, which is a kind of commitment to the network. There are two parts: CPU stake and NET stake. Both grant the user a proportional share of the total computing resources of the network: CPU is for computing power, and NET is for the bytes in the recorded transactions. Both regenerate over time if depleted. Additionally, the voting power of an account is proportional to the amount of EOS staked.
Staking is a one-time action recorded on the blockchain. A user does not need to do anything for their EOS to remain staked. However, in order to be able to move the staked EOS or a part of it, the user must first unstake the required part, and then wait for 72 hours for it to become available again. Thus staking represents some commitment, and the three days between unstaking and moving the funds can help prevent some of the damage if an account is hijacked.
Each action on the blockchain, including staking and unstaking themselves, consumes a certain amount of CPU and NET resources, depending on how long it takes to execute the action and how many bytes are needed to write it down. For common actions, the CPU consumed is much higher than the NET, in terms of staked EOS. So it is not uncommon to stake, for example, 1 EOS for NET and 99 EOS for CPU, if the total stake is 100 EOS. If the next requested action of an account exceeds its available resources, it will be rejected.
As for the wallet support, staking and unstaking are most likely the first actions supported by any wallet since staking is essential for any other actions.
For further reading, there's an explanation by EOS Canada: https://www.eoscanada.com/en/what-does-staking-and-unstaking-eos-tokens-mean.