How does CPU read data from the RAM?
There is throughput and latency.

On very simple, slow cores, the cache runs at the same speed as the CPU and can provide data in 1 cycle, so data is available immediately without stalling. When there is a cache miss, data is taken from main memory, and initial latency can be over 10 cycles. The good thing is that once the first data is available, the following data can be obtained quickly, hence the idea of burst transfers and cache fills. The CPU only needs a byte, or a 32bits word, but 32 or 64 bytes are transferred at once from memory to the cache.

On more advanced CPUs, the ones with L1, L2, DRAM and gigahertz clock, even the L1 cache contents cannot be obtained immediately.
For instruction, there are mechanisms for predicting the instruction flow and fetching instructions in advance : Continuously fetch consecutive addresses, unless the instruction is a branch, a call,...
For data, it is more complex. Using pipelining, some CPUs are able to have several outstanding data transfers before stalling. The real current solution for mitigating long latencies is out of order execution, the CPU does as much work as possible, even executing instructions not in program order, in order to hide the long latency of instructions like data reads and writes.