Not all journals have impact factors. Journals which are less than 3 years old generally do not have impact factors. Additionally, sometimes, journals that have had an impact factor for a long time might lose their impact factors if they have been unable to maintain their quality or have tried to persuade authors to cite articles from the same journal, or if the journal is unable to maintain the standard processes that are required for them to be included in the Journal Impact Factor (JIF) list. These journals however can regain the impact factor the next year if their processes are streamlined once again. Not having an impact factor does not necessarily indicate that the journal is a dubious one. In this case, the publisher is a reputed one: Elsevier, which is actually an argument in favor of the journal being trustworthy. I think you should check who the editorial board members are and see if the papers published in previous issues of the journal seem to be of good quality. Finally, you can ask your professors or senior colleagues in the field about the reputation of the journal. If it seems to be a trustworthy journal, there is no point in withdrawing your paper. However, if it seems to be a questionable journal, you can withdraw your paper. It is definitely possible to withdraw a manuscript after submission. All you have to do is send an email to the editor saying that you wish to withdraw your paper from further consideration by the journal. you should also ask the editor to send a confirmation of withdrawal. Your paper will be considered formally withdrawn once you receive the confirmation. Therefore, make sure that you do not submit to another journal before you receive the confirmation as this will be regarded as duplicate submission.