Everyone has a slightly different experience but these are the most common low back pain symptoms.

Stiffness that goes on for an hour or more in the morning may be caused by a problem that is not mechanical non-specific low back ache - it may a symptom of an inflammatory joint problem like ankylosing spondylitis. You need to tell your doctor about these symptoms.
You may feel stiff and sore when you get up from a rest or in the mornings. Usually this stiffness eases quite quickly with gentle movement or just getting up and about. For many people the stiff area feels better after 10-15 minutes.
This spasm is your bodies attempt to 'splint' or protect a sore area. If you have a sudden injury or strain this muscle spasm may be a good thing to start with.It reminds you to take it easy. After a day or two though this muscle spasm may become a
bigger problem than the original injury.
All these symptoms can occur in a muscle that has no injury at all, it may just be trying to protect a little underlying joint strain or something similar.
You may be going about your normal day to day business when perhaps you lift or carry awkwardly, or bend or twist - and then you feel a sudden, sharp stab of soreness that spreads across your back and feels worse as the day goes on.
Maybe you felt a bit of back ache after housework, or a slight soreness after a day sitting on front of the computer, maybe some aching after walking round the shops for a few hours. This noticeable soreness usually just goes away of its own accord - but before you know it, it creeps up you again another day. Gradually your back aches for longer and it gets harder to get comfortable pain relief
From years spent helping people with this problem I have recognised some typical patterns:
The good news is that for most people the problem is 'self-limiting' which means it normally goes away on it's own. The sudden, sharp soreness usually settles within 1-6 weeks, and most people feel much better before this.
Some people have to manage the problem for longer, maybe a year or more, and for others they have to learn to live with it because it never quite goes away. For an unlucky few, the problem interferes with their lives in a serious way.
Non-Specific or Simple Lower Back Pain Guidelines
Balagué, F. et al., 2012. Non-specific low back pain. The Lancet, 379(9814), pp.482–91.
02-Feb-2018