Best of luck on your journey! There are a bunch of possible side effects. I think constipation is probably the most talked about. As you increase your dose, nausea is common too. You'll likely feel more tired, mainly because you're eating less. Pay attention to your blood sugar levels; if you start feeling too weak or lightheaded, eat something.
Try to stay ahead of any constipation issues. Drink lots of water. I was using Metamucil twice daily, but I'm switching to magnesium to see if that helps more.
Be patient with your body. Take some before and after pictures. Measure yourself with a measuring tape at least once a month. If you don't already have one, get a smart scale to track your progress more thoroughly. It is really cool to see changes in body composition even when the scale doesn't budge.
One more thing: don't rush through the dose increases. Stay at the lowest effective dose. Many people don't see results on the lower doses, and it is fine to increase if you are stalled for a month, or your hunger isn't suppressed enough. But if you are still getting good results at a dose, don't increase it simply because the protocol says to go from 2.5 > 5 > 7.5, etc. The reason is: you can always go up later if you get stuck, but once you go up, your side effects might increase, and you'll eventually run out of increases. There are people who stay on a lower dose the whole time and do great, but others have to go up to the max dose to see changes.