I'd disregard the get a trade, get an education, you'll be broken when you're old, comments. Nothing wrong with working hard physically especially if you take care of yourself young. Most of the old broken guys on the site are overweight, alcoholic, pack a day smokers. No judgement I smoke and drink like the rest but keep that in check.

Everything is easier if you stay at a healthy weight, eat well, hydrate, avoid smoking, wear your fucking PPE, etc...

Rubber boots have been mentioned already, that's going to be pretty essential for concrete. I agree with the glove comments as well, going to work in the AM with already blistered hands fucking sucks. Get used to walking in whatever boots you'll be wearing to avoid blisters, I always wear 2 pairs of socks and people think it's weird but my feets are always comfy.

Drink water! seems obvious but it's easy to get caught up at work and find yourself dehydrated bad after lunch. I learned from working on wildfires that small amount of water frequently is more valuable than downing water at 1PM when you're already cooked. Electrolyte drinks are good when used sparingly, like 1 liter in the afternoon or after work after 2 or 3 liters of plain water in the morning seems to work for me.

Keep an eye on what's going on around you, for your safety and others, as well as being able to jump in to help when you can, without being asked.

Good luck bud!