Pressure with timing

For the test, 3 aspects are very important
1. Accuracy
2. Time management
3. Strategy

Since you’re in initial stage, ONLY concentrate on accuracy. Never mind the time. Once you are comfortable with the accuracy (I.e. If you can do most of the questions correct without timer), then start doing timed practise. Do timed practise with mix of questions (Low/Medium/High level) all together.
If the concepts are clear and the approach is correct, time will automatically fall in place.

Strategy comes into picture when you start giving mocks, which is a later stage.

All the Best

Posted from my mobile device

You've only been studying for a week. Even if you're already an expert problem-solver, solving problems with a GMAT timer is a new skill. Please don't stop working with a timer - it's something you really need to practice to master the test! But, what you're experiencing is completely normal and exactly what you should be doing right now. Go ahead and miss those problems when you do them with a timer, then review them later on with no timer. When you review, try to find ways to do them more efficiently. Then, come back to those problems after a week or two and do them again. See if this time you can get them right. If you're consistently taking too long with a certain type of problem (for instance, Geometry or Algebra) then spend some additional time studying that area.

You've got this and it sounds like you're doing everything right.