If you just want to run a dapp in sandbox environment you can run local EOS node (nodeos). It will contain only your data and will not sync all blocks from testchain.
You can start by downloading binaries of EOSIO and EOSIO.CDT.
and then simply starting local node through nodeos.
By default local node will run on http://127.0.0.1:8888/
Running a local nodeos instance is effectively a private network that exists only on your PC. In EOSIO it starts from complete scratch, so there are no user accounts or tokens present. E.g. to test out token transfers you would first need to build and deploy the EOSIO system-wide token contract.
There are several options for testing your smart contract and ...
Resources are managed by eosio.system contract, so if you don't deploy eosio.system to eosio account, there is no limitations on sending transactions.
For example, you can run single-node local testnet like this:
nodeos -e -p eosio --plugin eosio::chain_api_plugin
After launching single-node local testnet, create account by the next command:
cleos create ...