There are plenty of trainers to practice. Go where he plays is my opinion.
The thought of spending thousands to be part of a team. To spend 7,8 summer weekends on hot lacrosse fields. To lug equipment bags, water, gatorades, snacks, chairs, spending 7 hours on a field. Paying for hotels a couple more times in the summer. Sometimes lining up babysitters for your other kids at home, sometimes taking them, even though they will be bored.
If you can do all of the above and be ok with your son not playing. You are a much better man than me.