You don't mention a budget or preferred "star" rating, but the mention of Spa's says you're probably looking at the top end.

I think the Gran Hotel Costa Meloneras would suit the bill. It has an excellent but very reasonable spa, is in the smart resort of Maspalomas with a lovely beach close by, plus the legendary sand dunes, and also has the Campo golf course just behind it. Adjacent are some very smart shops and bars. You're outside of school holidays so there should be minimal children around.

We haven't been, but we saw it 3 years ago and once we'd picked our jaws off the ground (the infinity pool is stunning) vowed we'd stay one day and are booked to go later this year. I've kept a close eye on reviews (sadly, none yet on this site), mostly at trip advisor and they all seem excellent.

If you have Google Earth loaded it's very well defined. Find the Maspalomas dunes to the west of Playa del Ingles, keep going west and you'll see the lighthouse. The hotel is just adjacent to the west, you can't miss it, it's huge and has about 5 pools.

There is golf dotted all over the island, evrywhere, especially maspalomas has a lot of golf, golf dedicated hotels and apartments.

I'm not really sure if the Gran Hotel Costa Melonaras would suit the bill. I am a pensioner and the last time I visited this hotel a lot of people staying there were people in my age group as were the people playing golf on the nearby golf course. In fact a lot of pensioners are often the only people who can afford to stay in upmarket hotels these days so you may have to look elsewhere for hotels that do not cater to "old people"

You may find the Green Oasis Bungalows a good choice, and a well priced All Inclusive choice as well. This is in Maspolomas which is a suitable resort for what you are looking for.