Job offers?!

So recently I received a job offer for a job which is slightly away from home (an hour on public transport). I accepted the offer because at the time it was the only job offer I got after applying for a number of jobs. FYI: this was almost a month ago and I'd been waiting on DBS checks etc

Whilst waiting I decided to apply for other jobs. 2 better jobs have come up and I am waiting on finding out if I will be offered them (I think I will as I have the relevant experience/qualifications..but it will depend on if they find someone better lol). Anyways, I'm confused as to what I should tell the company I've been offered a job at? Should I wait until I get the job offers from the others and find out start date?

Or should I begin my job at the new place (I think it will be in a few weeks) and then leave if something else comes up?

For some reason I feel terrible for accepting the offer and then finding something better and still not telling them yet!

Someone tell me please as it will be my first proper job related to my degree so I have no clue!

You should definitely wait on other job offers if you feel it is more of a fit for your career/degree.

Tell them you are excited about their offer but are in the late stages with another company and would like the opportunity to see the process through. Ensure that you don't give the impression that you're starting new applications, rather you're finishing the interview process that you've already started.

They should understand your situation as this is a common scenario for many people.

With your preferred job (the ones you're waiting on), it may be worth asking them for an update as you are also waiting on other offers and you're really interested in this job.

I signed the contract for this job about a month ago. This was when I wasn't successful for any jobs for almost 6 months (so I was desperate and signed). Do you think this will be an issue? I really don't want to make a silly decision lol