I st holiday outside UK but where?

And Turkey is still warm in September.

I agree with granny23 and think that Nerja [Spain] would be a good first holiday abroad. We have been there twice recently.A small town, easy to get around and right on the coast.Friendly, and most people there speak English.Lots of little streets full of shops to explore, and tons of places to sit out and have a coffee.A lot of older people seem to like the town, and it feels safe.You can walk as much or as little as you want.The hotel we stayed in was right by the sea,and if you go with Thompsons or a company like that there will be coach tours to go on[if you like to do that.]In September it will be hot [guaranteed] and although I love Lake Garda [In Italy] in September you could get rain and mists.

It depends on your interests.
What might be an ideal holiday for me might not suit you.

Depends where you travel but some countries require you to have a Visa and this is based on nationality so look for the requirements on the countries Embassy site. You may be able to buy on line, in an airport or arrival dock or border crossing.
If you go on a package holiday your holiday company may be able to advice on this or even purchase the Visa for you but you will pay for this service.

If you think you may need inoculations go to see your healthcare professional with a list of the countries you will be traveling too and they will advice you on any inoculations etc you may need to have before traveling.