Welcome to GOY Detta at this time would just recommend mowing lawn regularly as this in itself will reduce some weed content.Weed and feed can scorch lawns during the summer so best to wait till autumn for lawn treatment.

Moss and low growing weeds can be scarified out at this time .. doesnt look pretty when done but allows plenty of time for spring re growth.A good autumn feed afterwards encourages grass root growth.

As regards your borders being a new home you may have bulbs and other plants waiting for spring so would nt recommend any type of weed killer if too much to dig out just placing sheeting over weeds for a couple of weeks will diminish them.

Welcome Detta to a great site for help and good company. you are going to have so much fun waiting to see what comes up and then planning what you are going to grow. I can imagine how excited you must be to have your lovely new home and brand new garden.

Lawn weed and feed treatments should not be used past the end of July, so you will have to wait till next April before using it - usual procedure is, if its granular, apply in April and then again six to eight weeks later.
For the paths, you can get path weedkiller treatments specifically for those areas, but they must not be used on the soil or anywhere plants are growing, only on paving and paths. Best applied in late spring, a good one like Pathclear will keep the weeds away for 3-6 months, depending which formulation you use, though you can apply it now if you want, but most weeds disappear during the winter anyway.
As already said by others, cutting the lawn regularly helps to keep weeds down and give a better lawn. If you have the time and energy, in September, scarify and aerate the lawn - it will look dreadful as Bonkersbon says, but will give you better results next year.

Thanks a real lot for the answers.

Before moving to this house, there was nobody living for over 2 years, so I doubt there are any flowers blooming in Spring. I will start deweeding the borders, and if there are any bulbs will leave them there...

Still undecided whether to place gravel in the pathways though.. any ideas?

Guess it depends on what you want from this area Detta you really have a blank canvas so to speak its very square and formal and if that suits you then fine.Before gravelling paths you need to consider what style of garden you would like.

Modern , informal , cottage garden? Maybe a pond? You have children that need a play area etc? Once these things decided garden can be planned around them.

I'm not clear as to why you'd want to place gravel on the pathways, can't see what benefit this would bring - it would attract cats who love to use it instead of cat litter, its uncomfortable to walk on, particularly when on top of hard surfacing, and in a torrential rain situation is liable to be washed to the lowest point of the garden. Gravel is usually laid onto soft surfacing, like soil with or without a membrane, and compacted down.