Starting keto, when to start exercise?

Hello folks! My wedding is coming up in September 2022 and I'm hoping to lose about 20lbs+ by then. I was on strict keto last summer and my weight loss went well.

Then we got engaged and bad habits slipped back in along with the celebrations.

I don't feel my eating habits are terrible or that my weight gain was significant - maybe half a dress size up. I still fast about 18hrs and eat about two small meals a day with no "classic" carbs like pasta or potatoes, although I'm not counting them so it's not strict by any means.

My exercise, however, is non existent except for an hour long dog walk every day. And sadly, I've picked up my smoking habit again since last year. Which is probably the most disappointing for me, but I feel important to share here because I do feel it slows my weight loss. (But I am taking action on stopping so hopefully I'll quit within the next few weeks for good.)

What, in your experience, is a good way to bring back exercise when starting keto? Years ago I did spinning and the weight fell off so I was thinking of doing this again because I'm getting a bit nervous about how close I am to my wedding date, but I'm worried about the early keto energy dip and being so unfit / a smoker will make it a real struggle to stay motivated and will counter my effort.

At the same time, I want to feel fit, strong, healthy and energetic again beyond just losing weight.

Tips, encouragement, experiences so welcome!!! 🙏